Riddle for the Ages

It's been 25 years since it happened, and he still doesn't know how that pineapple ended up on his nightstand.

"There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy."

It is the nature of mysteries that people want to find answers, and since fiction is in the business of giving people what they want, just about any mystery introduced in a story is going to be resolved. Important character gets murdered? We're gonna find out who the culprit was. The Eiffel Tower disappears? We're gonna find out where it went and why. Someone blacks out and wakes up three days later wearing antique samurai armor and a pink cowboy hat? We're gonna find out what led them to that state of affairs. While mysteries might sometimes be left unanswered inadvertently (such as a series being abruptly canceled, or the writers simply forgetting the mystery exists), if the people in charge know what they're doing, for every mystery introduced there's going to be an answer introduced somewhere down the line.

Except when there's not. Sometimes writers will create a mystery but never have any intent of actually giving us an answer. Bob will wake up one day with his right leg amputated, or Alice will discover someone's rearranged all her furniture while she was out. They might brush these matters aside cavalierly, or they might become obsessed with discovering the truth, but eventually they come to realize that, if they're ever going to get an answer, it's not going to be any time soon, and write off their respective mysteries as "one of those things".

This might be done for comedic effect, as part of a Mind Screw, or just to reflect reality. After all, how many of us have had something weird happen in our lives but never discovered the "why" behind it all? Like all tropes this sort of mystery can be used to tell really good or really horrible stories depending on the writers' skills, though it's generally considered good form to, if you're introducing an answerless mystery, let your audience know they're not getting an answer. It's not quite fair to present viewers a mystery, suspects, and clues that clearly have some sort of resolution, if only in the author's head, but never say what it is. Make it clear that you're not going to let people in on an important secret that you or someone on the production staff knows the answer to, and years might go by and people will still be asking you, "Why did X commit Y on Z?"

Please note that, to keep the examples section from getting bogged down, we should list only cases where a mystery is left unanswered and, either through context within the story or via Word of God, we know it was never meant to receive an answer. Without either of these things, it should be assumed that the writers meant to answer the mystery, but have not yet gotten around to doing so.

Super Trope of Maybe Magic, Maybe Mundane. Cousin of the Cryptic Background Reference (they both add to the sense of a larger universe by leaving unexplained mysteries). See The Unreveal. Compare Noodle Incident, The Unsolved Mystery, What Happened to the Mouse?, Missing Secret, and some Big Lipped Alligators. May lead to Wild Mass Guessing and Epileptic Trees.

Not to be confused with A Riddle Wrapped in a Mystery Inside an Enigma.


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    Anime and Manga 
  • Baka to Test to Shoukanjuu: In-universe, the question of Hideyoshi's gender is this. In the light novels, it's eventually confirmed that he's a boy. You know, like he's been claiming the whole time.
  • In Code Geass, CC tells Lelouch her real name, but the sound is muted the exact moment she says it, preventing the audience from finding out. The same happens when Lelouch repeats it to her.
  • Did Bradley from Fullmetal Alchemist love his wife? He openly admits that he considers himself superior to humanity, but he also says that his wife was the one thing about his life that he himself chose. As he dies, he says that he has no message for her because that's the relationship of a king and his wife.
  • 7 Seeds has an in-universe example. The Ryugu Shelter arc has a mangaka in its mist, who works on the manga Wonderful Q. The driving question of the manga is the protagonist looking for the answer of "What is 'Q'?". The final chapter of the arc shows Mark picking up a page of the final chapter, revealing that the protagonist had found the answer, though the reader is never shown. So... what exactly is Q?
  • In Maison Ikkoku, after fourteen volumes and some six years of in-universe time, neither the readers nor the other characters have any real idea of Mr. Yotsuya does for a living...or, indeed, any knowledge of his life outside the apartment. His one and only Day In The Lime Light is devoted to him evading the other characters' attempts to figure out what he does all day.
  • Pokémon
    • Nurse Joy and Officer Jenny. Maybe they are simply just the female members of extended families who happen to look exactly alike and who all choose the same career, but fans have to wonder. And it has been explored a lot in fanfics.
    • What the heck happened between Brock and Prof. Ivy?
    • Who is Ash's father? Word of God was that they would bring him in if he would be important to Ash's development.
  • An episode of Naruto is dedicated to Naruto, Sakura, and Sasuke trying to find out what Kakashi looks like underneath his mask. Neither they nor the audience ever get a look at it, but it can apparently make Even the Guys Want Him.
  • Some questions that Neon Genesis Evangelion leave unanswered:
    • What did Gendo say to Ritsuko before he shot her?
    • Which ending (TV or movie actually happened? Is the movie ending taking place for real, or is it just what Shinji wanted out of Instrumentality?
    • Whose soul is in Unit-00?
    • Why did Shinji saw a Rei hallucination when he first came to Tokyo-3?
    • What did Asuka mean exactly by her "How disgusting"/"I feel sick" in End of Evangelion?
  • Dragon Ball: what was Darkness actually?
    • Dragon Ball Z: The name of Freeza's race, despite several new members of it being introduced in various DBZ-related works, has never been revealed.
    • The real names of Androids 17 and 18 were this for a long time until Toriyama revealed their real names: Lapis and Lazuli.
  • In Mobile Suit Gundam SEED, a few episodes after their breakup, Flay wanted to speak to Kira, but he says it will have to wait 'cause he's heading to battle. He promises they'll talk after, but they never get a chance to meet face to face again. We never found out what Flay wanted to say as she wasn't in her usual bitch mood and sounded apologetic when she approached Kira.
    • In the original Mobile Suit Gundam, it's never made entirely clear whether or not the Zabi family really did assassinate Char's dad, Zeon Deikun. The official story is he died of a heart attack but Char himself and most other people who mention his death treat the assassination angle as an Open Secret. Mobile Suit Gundam The Origin, however, implies that the assassination theory might have been cooked up by Deikun's Old Retainer Jinba Ral both to discredit the Zabi family and to mold Char into a Tyke Bomb against them. In the end, it's one of those enduring mysteries that conspiracy nuts of the Universal Century will debate for centuries, until the Turn A Gundam kills them all.
  • Played With in one of the prequels of Legend of Galactic Heroes, where Yang Wen-li investigated a mysterious weekly correspondence which asserted that the Alliance war hero Bruce Ashbey was murdered and not killed in action as popularly assumed. He ended up uncovering circumstantial evidence that Ashbey was the recipient of leaked intelligence provided by a massive secret espionage network established by a disaffected Imperial noble. The actual existence of such a network was however never revealed in the story and Yang himself asserted that his hypothesis might never be proven unless both the Alliance and the Empire ceased to exist.
  • Jojos Bizarre Adventure, Diamond is Unbreakable: Is Mikitaka an alien or just a weird human?
  • Sonic X: Who or what was "Nazo" supposed to be?

    Comic Books 
  • The identity of the Joker, Trope Namer for Multiple-Choice Past.
  • Seen in Tintin's adventure Tintin Land Of Black Gold: Captain Haddock shows up to rescue Tintin even though he was half a world away, and never gets around to explaining how that was possible. He's interrupted right after "It's both very simple and very complicated." or "Well, you see, it's like this..." in the English translation.
    • The lack of explanation for Haddock's appearance is actually a meta joke: the original version of Land of Black Gold was initially serialized in a newspaper in 1939 and 1940, but after Germany occupied Belgium in 1940, Hergé thought that the comic would not pass the German censors because to its political nature, so the publication of Land of Black Gold was stopped mid-story. At this point Captain Haddock hadn't yet been introduced in Tintin, so naturally he didn't appear in Land of Black Gold either. Several other Tintin stories were published before Hergé decided to redraw Land of Black Gold in 1948, and in these intervening stories Haddock had become the most significant character in the series besides Tintin himself. Thus it would've been odd if Haddock had been left out of the new version of Land of Black Gold, but on the other hand he didn't really belong to a story that had been scripted before he even existed. This is the reason why Haddock is virtually absent from the story until the very end, and why there's no explanation for his sudden appearance. The lack of explanation is Hergé's comment on Haddock "invading" a story he wasn't originally a part of. So there is a solution to the mystery on a meta level, but not in the text.
  • In Gaston Lagaffe, what are those contracts about that M. De Mesmaeker is always trying to sign?
  • In Y: The Last Man, no one knows what caused the Gendercide. While several theories are made in the story, and Word of God confirms that one of those theories is true, he refuses to say which one. Yorick even invokes Fan-Disliked Explanation in-universe after an encounter with a Mad Scientist.
  • The Dan Dare story "The Red Moon Mystery" concerns an asteroid-like object that can move freely in spaaaaaaace to attack other planets despite being home to nothing but some bee-like insects. Dan and co are ultimately forced to destroy it before they can discover how any of this works.
  • Is Deadpool really Wade Wilson or not? Is T-Ray the real Wade Wilson like he says or is he just lying or crazy? Did a guy named Wade Wilson ever really exist to begin with? Nobody knows for certain and probably never will. At the very least, Deadpool himself seems pretty sure that he's the real Wade Wilson but this is Deadpool...
  • Did Cerebus go to Heaven or Hell at the end of Cerebus the Aardvark? Cerebus seems certain that it's Hell but it's not explicitly stated.
  • In The Walking Dead it's never revealed what started the zombie outbreak, because the interaction between the characters is more important.
  • Judge Dredd: What does Judge Dredd look like? It's an enduring tradition of the comic not to reveal the face behind the helmet.

  • Used for purposes of Mind Screw in the French film The Moustache, which also has No Ending. The protagonist may or may not have Ripple-Effect-Proof Memory, with someone or something repeatedly changing the world around him. He also may or may not be the only one getting messed with, and it's left uncertain whether he'll ever figure out what's going on and how to end it.
  • The contents of the suitcase in Pulp Fiction. Though Tarantino said it's diamonds. Samuel L Jackson, meanwhile, said it contained "two heavy-ass batteries and three lights."
  • The final scene of Inception, in which it is purposefully unclear if Cobb has finally seen his kids or if he is dreaming. Cobb spins a top to test whether or not he is dreaming; if it stops spinning, he is in the real world, but the film invokes a Smash to Black before this happens.
  • The contents of the silver case in Ronin. The main characters even demand more money because their employers refuse to tell them anything about it.
  • The contents of the unopened package in Cast Away. When pumped for an answer, the creators joke that it's a solar operated waterproof satellite phone. The third draft of the script has it containing two jars of salsa verde and a note.
    • There was actually a FedEx commercial referencing the satellite phone explanation, where he gets back to civilization and actually delivers the package. Just out of curiosity, he asks the recipient what was in it. Not only was there a solar operated waterproof satellite phone, but also seeds and water purifier tablets, "you know, little things".
  • In Cache, we never find out who sent the tapes, or why. There are many clues, but no answers.
  • The Dark Knight: What is the backstory of the Joker? It's even a specific trope.
  • Star Wars
    • The exact name and homeworld of Yoda's Species are still unknown. Revealing these facts is one of precisely two things Expanded Universe authors are forbidden from doing by George Lucas himself. The other is showing how Luke, Han, or Leia dies.
    • What jawas look like under their hoods.
  • In The Maltese Falcon we never do find out what happened to the original.
  • What's whispered at the end of Lost in Translation? Audio clean-up suggests it's "I won't see you till the next making of Suntory. Go to that man and tell him the truth, okay?" However, this is irrelevant; Sofia Coppola didn't write any lines for the scene, she just told Bill Murray to ad-lib something.
  • In Fright Night, we never do learn what Billy Cole was, only that he was neither human nor vampire. The novelization shows the heroes are as perplexed about this as the reader.
  • In the Disney film Candleshoe, Jodie Foster's character is hired by a con artist to pose as the Long-Lost Relative of an English noblewoman. At the end of the film, it's suggested that Foster's character might actually have been the person she was impersonating, but we don't find out for sure.
  • In The Day the Earth Stood Still, Klatuu tells Helen that if he is killed, Gort will destroy the Earth, and to stop him, she must use the code word ""Klaatu barada nikto". She successfully does so, but exactly what the phrase means (obviously, it's something in Klatuu's language) has never been truly revealed. Word of God is actually contradictory on this. The film's director, Robert Wise, related a story he had with Edmund North, the screenplay writer, saying North told him, "Well, it's just something I kind of cooked up. I thought it sounded good." On the other hand, Billy Gray, who played Bobby Benson in the film, said that "barada nikto must mean... save earth". Florence Blaustein, widow of the producer Julian Blaustein, said North had to pass a street called Baroda every day going to work and said, "I think that's how that was born." Film historian Stephan Jay Rubin claimed that in an interview he had with North when he asked the question, "What is the direct translation of Klaatu barada nikto, and Edmund North said to me 'There's hope for earth, if the scientists can be reached'."
  • In The Quiet Man Mary Kate whispers something to her husband Sean Thorton which gives him a shock. This is also a Real Life mystery, as director John Ford told Maureen O'Hara to whisper something shocking to John Wayne to get that reaction. The three of them never explained what was said... And unless O'Hara mentioned it to someone else for posterity, when she dies the secret dies with her.
  • The Hangover: What the hell happened to that chair? And why was the chicken there?
  • Street Trash: What is Viper, why does it melt people, and how did it end up in the back of the bar?
  • In K-PAX, was prot a delusional savant, or genuinely an extraterrestrial from the planet K-PAX?
  • Upstream Color: Where did the mysterious blue substance come from, and what was the relationship between the Thief and the Sampler?
  • Pirates of the Caribbean: How did Cotton manage to teach his parrot to talk for him?
  • The Wicker Man: Willow's attempts at seducing Howie is never explained.
  • Played for laughs in The Adventures of Buckaroo Banzai Across the 8th Dimension:
    New Jersey: Why is there a watermelon there?
    Reno: I'll tell you later.

  • Frank R. Stockton's The Lady or the Tiger? In the story, a king forces each criminal to choose one of two doors. Behind one is a beautiful maiden that he will instantly marry. Behind the other is a ravenous tiger that will tear him to pieces. One criminal is the lover of the princess, who knows which door leads where. She gestures toward a door, and he opens it, but what does he find? Could the princess bear to see him marry another woman, or would she rather he died? The story caused something of a sensation in the years following its release, with readers clamoring to wring an answer from the author. A common writing assignment in classrooms is to supply an answer to the question.
  • Alice in Wonderland:
    • "Why is a raven like a writing desk?" The riddle is never intended to have an answer, prompting many fans throughout the ages to supply their own answers:
      • Sam Loyd's "Because Poe wrote on both" is the most popular answer.
      • "Because the notes for which they are noted are not noted for being musical notes." Sam Loyd again.
      • Stephen King's "The Shining" has a rather good answer for that: "The higher the fewer, of course."
      • Carroll himself eventually supplied his own answer, but only after years of people asking: "Because it can produce a few notes, tho they are very flat; and it is nevar put with the wrong end in front." Note that "nevar" is "raven" spelled backwards.
      • "Because there is a B in both and an N in neither." (Aldous Huxley)
      • "Because it slopes with a flap." (Cyril Pearson)
      • One Two Lumps strip both re-uses the above "Poe wrote on both", and also suggests "Both have inky quills."
      • From Sir Apropos of Nothing, "Because it is only with quills that they truly take flight."
    • Another one: Was Through the Looking Glass Alice's dream, or the Red King's dream?
  • The Lord of the Rings: What is Tom Bombadil?
    • What are the origins of the Orcs?
    • What other evil creatures, which were worse than the Balrog according to Gandalf, were buried under Khazad-dum?
    • Who were the Ringwraiths before they received the Nine Rings? We know that three (probably including the Witch-king) were Numenoreans, and that Khamul (the only Ringwraith to be named anywhere by Tolkien) was an Easterling king. Other than that, nothing.
    • Where did Radagast and the blue wizards go?
    • What happened to the Entwives?
    • Was Sam allowed to cross the sea to Valinor? According to his relatives, the answer is yes, but no-one actually knows.
    • The Silmarillion: Where do the souls of dead Men go when they leave the Halls of Mandos?
      • What was the 'First Fall of Man' that Tolkien claims happened before Men arrived in Beleriand?
      • Did Amandil reach Valinor?
      • What is the origin of Ungoliant?
  • The Virgin Suicides: Why did the girls kill themselves?
  • The Hitchhikers Guide To The Galaxy: What is the Ultimate Question of Life, the Universe and Everything? Simultaneously knowing both the Ultimate Question and the Ultimate Answer would cause the universe to rearrange itself into something even more incomprehensible. This may have happened already.
  • A gag in More Information Than You Require involves Hodgman's encounter with director Peter Berg on a plane and finding out he had two copies of Dune with him on the plane, because he was planning on making a Dune movie. This does not explain why he had two copies with him. This becomes a brief running gag, in which Hodgman provides even less helpful explanations that still don't explain why he would have two copies of the book, leaving it a mystery to us all. note 
  • This is the whole point of Special Topics In Calamity Physics, which sets up dozens of mysteries and hardly answers any of them. At the very end of the book, the narrator gives a "quiz" in which she asks readers to come to their own conclusions on what happened. Ultimately, the implication is that it doesn't matter, because the narrator has moved on and grown through the experience.
  • Stanislaw Lem's Solaris: Why did the planet send the replicas of people? The main theme of the novel is that we can't find out, because humans can't comprehend a truly alien intelligence.
  • 1984 raises the question of whether Emmanuel Goldstein and his revolution against the Party actually exists, or if they're simply a fabrication the Party uses as a target for the population's hatred and as bait to weed out dissidents. O'Brien states quite firmly and adamantly that Winston will never learn the truth about this.
  • In Tim Powers' On Stranger Tides, a pirate decides he'd rather be shot than hanged, and asks his Navy captors' leader an Armor-Piercing Question ("Is it true what Panda Beecher once told me about you?"), that implies the captain is either a smuggler or a sexual deviant. This provokes a fight in which the enraged captain is killed. After escaping, the pirate explains his ploy to his accomplice, and admits that he hadn't actually known anything about the captain: he just knew lots of Navy officers smuggled for Beecher or patronized Beecher's whorehouse, and they'll never know which offense the dead man assumed he'd been accused of.
  • In The Shining — who is the Manager of the hotel that the ghosts refer to?
  • In The Tripods books, there are suggestions that the Sphere Chase is more than just a sport. Our heroes first become aware of it when they encounter two tripods practicing for it while on patrol. After Ruki is captured, he refuses to discuss the game, even though he does answer questions about the city and his race which are far more damaging.
    • An initial theory is that the tripods could be mating, however this is proved incorrect when the main characters find out the Tripods are just vehicles for aliens, not aliens themselves.
  • Why did Dracula move to the US in the 1970s? This is a minor Running Gag in Fred Saberhagen's New Dracula series. Several times someone asks Dracula why he left Europe and he starts to reply with something like, "I came here because I like your—", only to be interrupted before he can finish by an American talking about something else.
  • In the Sherlock Holmes story The Five Orange Pips, while Holmes's explanation certainly makes sense, the mystery is never conclusively solved, as the primary suspects vanish without a trace with only vague hints as to their fate.
  • In David Copperfield, Ham Peggotty swims out to sea to save a shipwrecked man from drowning. Shortly afterwards, both their bodies are washed up on the shore and the other man turns out to be Steerforth, who seduced and then cruelly abandoned Ham's fiancée Emily. It will never be known whether Ham tried to save Steerforth or drowned him.
  • In Algernon Blackwood's "The Man Who Found Out", an explorer discovers the ancient Tablets of the Gods, reputed to explain the true purpose of human life. Once translated, their revelations cause him and the friend who inherits the Tablets to succumb to despair, then go to extreme lengths to conceal their contents: contents that the reader never learns, apparently mercifully.
  • A Series of Unfortunate Events loves this. What were the exact circumstances surrounding the death of the children's parents? What was the cause of the schism in VFD? What was the exact cause of the death of Olaf's parents? (All we're told is that it involved poisonous darts and it was hinted that the children's mother was a part of it). What happened to the people living on the island? Did they reach the horse radish factory in time, or did they die of the spore poisoning? What happened to Fiona, the hook-handed man, Hector, Duncan, Isadora, and Quigley? What is the Great Unknown? What was in the Sugar Bowl, exactly? What was the fate of the guests at the hotel? Who was the father of Kit Snickett's baby? That's not even half of them all.
    • There was also a scene on an island that everything washes up on eventually. They listed quite a few objects and vaguely hinted of the stories behind them.
    • The Great Unknown's identity has been hinted by the prequel All the Wrong Questions to be the Bombinating Beast, a Cthulhu-esque urban legend, a statue of which is the story's main MacGuffin.
  • Machado de Assis has a book that's been interpreted in different manners since 1899. The story is about a man that tells his life, his love for Capitu (his wife) and the doubts about her adultery. No one could ever tell if the protagonist was right, that his wife cheated him, or if the madness and the jealousy have taken their toll. Even today.
  • In The Princess Bride, William Goldman (who claims to be merely editing the original Morgenstern) notes that the original manuscript ended on a 'Lady or the Tiger'-esque note, with Humperdinck and his cronies pursuing the four fugitives, who experience a number of setbacks. He further claims that it's left permanently open-ended as to whether or not they got away and lived Happily Ever After, but that as far as he's concerned, they did. Of course, Goldman is the actual author of the book, so the ending isn't really ambiguous.
    • For an anniversary edition of the book, Goldman included the first chapter of the "sequel" (which, according to his Literary Agent Hypothesis, he can't publish in full because the rights to the original work were given to Stephen King instead). The chapter picks up where the previous supposedly left off and then goes in a very strange and fantastical direction.
  • The Big Sleep: Did the chauffeur commit suicide, or was he murdered? When the producers of the film asked Raymond Chandler, he realized he'd forgotten to answer the question and didn't know himself.
    • It has been suggested that Chandler gave this answer because he was miffed at William Faulkner being asked to write the screenplay rather than him, and actually knew who killed the chauffeur. In Where was Rebecca Shot?, John Sutherland points out evidence within the text that indicates the chauffeur was killed on the orders of Eddie Mars. But there is no definitive answer.
  • The Inspector Morse short story "Morse's Greatest Mystery". The initial crime (a theft) is never resolved, or even substantially investigated.
  • Lieutenant Hornblower leaves unanswered a question that formed a key plot point in the novel: How did Captain Sawyer fall down the hatchway? Did he fall? Was he pushed? If so, by whom? This is the only Hornblower novel not to be told from the titular character's perspective, and in the story itself, Lieutenant Hornblower is quick to begin an investigation of the incident during the confusion left by the Captain's incapacitation, with the only other witness to what happened being his assistant. By the end of the book, the other man has died in a shipwreck, and Hornblower himself never reveals the answer.
  • More Than This leaves a couple of mysteries unresolved at the end of the book: What caused the fire that burnt down the area on the other side of the train tracks? Who or what is the Driver, and why did he save Seth's life, after seemingly trying to kill him?
  • In Harry Potter And The Order Of The Phoenix, what was behind the impossible-to-open door in the Ministry of Magic, that not even the Alohomora charm could unlock? It's hinted the Ministry are researching The Power of Love in there, but why that room alone would require such powerful defenses is never revealed.

    Live Action TV 
  • Another example of Steven Moffat as a Trolling Creator in the pilot of Sherlock. Which bottle was it? Come on. Play the game. Also, in the third season, how did Sherlock Holmes and Jim Moriarty fake their deaths?
  • In Buffy the Vampire Slayer, what was Buffy's heaven? Was "Normal Again" true? How did Warren learn how to build Ted-level robots? How did Anya cause the Russian Revolution? Exactly how close were Ethan and Ripper? What is the origin of Faith's tattoo? (explained in one of the books; it's the Mark of Kakistos, gotten while she was being possessed by a pissed off dead Slayer.) Did the PTB extract Angel from that Hell Dimension? How did Buffy and the gang save the world and from what in "The Zeppo" (the episode focused on Xander and an unrelated event, so the audience only gets glimpses of what Buffy's doing)? The goddamned Cheese Man.
  • Seinfeld is the Trope Namer with the episode "The Pie." The very first scene of the episode has Jerry offering his Girl of the Week a slice of apple pie, which she refuses to taste. She doesn't give a reason, just shakes her head, and Jerry becomes obsessed with figuring out why she won't try the pie. He rules out a lot of possibilities, but by episode's end, he's still as clueless as ever.
    George: Did you ever solve the riddle of the pie?
    Jerry: No, that's one for the ages.
    • In "The Seven", Jerry dates a woman who always appears to be wearing the same dress. He wonders if she never changes her clothes, if she has a closet full of dresses like that, or if it's something else entirely. He never finds out and neither does the audience.
  • In the How I Met Your Mother episode "The Pineapple Incident," Ted gets drunk, blacks out, and wakes up the next morning with a sprained ankle, a burned coat, an unknown phone number written on his arm, a woman he doesn't know in his bed, and a pineapple on his nightstand. Through some detective work, Ted discovers exactly what he did while drunk to cause each of those things ... except the pineapple. Future Ted confirms that he never did find out where the pineapple came from. But it was delicious!
    • The woman, Trudy, makes a post on the website Ted Mosby is Not a Jerk. It doesn't reveal much about the pineapple, except for the fact that Ted probably shouldn't have eaten it.
    • In a bonus scene released after the show aired, Ted stole the pineapple from The Captain who keeps pineapples outside his homes as a sea captain's symbol of hospitality.
    • In the episode "Zoo Or False", we don't find out how Marshall's wallet went missing. Nor do we find out whether Bobo really escaped from his cage, stole a doll and climbed Ted's model of the Empire State Building.
    • What does Barney do for a living? We know where he works, but not what he actually does. Even Marshall, after working with him for a time, doesn't know what he does. He changes the subject whenever he's asked about it directly. This is finally subverted in season nine where we find out that whenever they asked Barney about his job, he told exactly them what his job title was but they did not understand that PLEASE was actually an acronym. His job is to be the Fall Guy for all of the company's wrong doing but he actually is an FBI informant.
  • House:
    • When Kutner killed himself, there was no buildup leading to his suicide, and in the aftermath no one was able to find any reason why he might have done it. Since House's main source of fun in life is finding answers to mysteries, he finds this extremely frustrating.
    • No explanation was ever given, nor intended, for why House was shot in the second-season finale. Nor for what became of "Harpo" in the same episode.
  • Parodied in the Mystery Science Theater 3000 episode Prince of Space: Japanese reporters are awaiting the scheduled arrival of a spaaaaaaace invasion:
    Reporter #1: One minute to 8:00.
    Reporter #2: Is your watch right?
    [A noise is heard and everyone suddenly goes to investigate]
    Mike: (Somberly) Is his watch right? We may never know.
  • In Twin Peaks, the question "Who killed Laura Palmer?" was intended to be one, but was forced to be resolved due to Executive Meddling.
  • On Top Gear, the real identity of The Stig. Or the age of The Stig. Or the origin of The Stig. Or pretty much anything about Stig beyond "tame racing driver." There was some suggestion that the Stig is in fact Michael Schumacher, but after he got lost on the test track it seemed disproved.
  • Farscape: who killed Salis? Chiana, Durka or somebody else (there's a widespread Epileptic Trees theory that it was Zhaan)?
  • In one episode of Boy Meets World the characters engage in an Escalating War and it's never explained how they pulled off certain outrageous pranks. Like, how the hell did Cory and Shawn move Rachel's car into her dorm room? And where did Rachel, Jack and Angela get that bear?
  • In One Foot in the Grave:
  • What was in the Christmas present from her parents that Temperance finally opens at the end of a Bones Christmas Episode?
  • Many plot points of LOST are considered this, but for a specific example, the identity of the shooters in the second outrigger ("The Little Prince", Season 5) became sort of a running joke among the producers: due to Time Travel being involved, too many possible candidates for the role exist and not once has an attempt been made to narrow the circle down.
  • Doctor Who:
    • The Doctor's backstory was clearly intended as this during the show's early years. His backstory is fairly well-codified now (save for some prominent gaps that simply cannot be answered without derailing the show), but the show ran for over a decade before the Doctor's home planet was even named, let alone running arcs about him becoming Lord President of Gallifrey.
    • What's the Doctor's real name? During the Steven Moffat years, this becomes an actual plot point in-universe: the oldest question in existence, which must never be answered, is revealed to be "Doctor who?" It's revealed why the question's so important at this point during the Doctor's life in "The Time of the Doctor", but the crisis gets resolved without answering it, or revealing why his name is a secret in the first place. The question gets asked during a different crisis in "The Name of the Doctor", but while it does get answered then, it's still never revealed.
    • Similarly, in Who spin-off Torchwood, Captain Jack Harkness reveals that he took his name from some poor soldier who died in WWII. So... what was he named before that? We don't know. Even his brother calls him 'Jack'.
    • In the non-canon episode "Curse of the Fatal Death" his companion frequently asks "why/how/what [whatever]?" and he always answers "I'll explain later," but the explanations never happen. This is a reference to the many, many times he said "I'll explain later" or something similar on the show. There used to be a website that listed every instance, but it seems to have disappeared. Specifically, why the Daleks chose to not exterminate the Doctor and Emma, why there are chairs on a Dalek ship, and exactly why the Master is called "The Master". He is called "The Master" because he chose to call himself "The Master", for pretty self explanatory reasons. Also, it's a play on the fact that both "Doctor" and "Master" are academic degrees.
    • Throughout The End Of Time, a mysterious woman continuously appears to Wilfred Mott, steering him towards meeting the Doctor. At the very end, she appears alongside the Big Bad, and her presence is enough to convince the Doctor out of attacking him, and apparently getting Killed Off for Real. Once everything is over, Wilfred asks the Doctor exactly who she was. He never gives an answer, and immediately changes the subject.
    • "Deep Breath:" Did the Doctor shove the Big Bad off the hot air balloon, or did the Big Bad jump?
  • From Stargate SG-1, who were the aliens whose ship attacked the Prometheus in "Grace"? Who and what the Furlings were is also never stated.
  • Horatio Hornblower: What happened in "Mutiny" when Captain Sawyer fell down the hatchway? Was it an accident? Or was he pushed? If he was pushed, who pushed him?
  • Who beat Dr. Greene to a pulp at the end of season 3 of ER. The assault causes Greene to temporarily go off the deep end and start stalking Chris Law, the disgruntled brother of a man who died under Greene's care, but Law is ruled out as the culprit and in fact Greene ultimately apologizes to him.
  • In the Diagnosis: Murder episode "Rear Windows '98" the culprit is caught, but he refuses to say why he did it when questioned.
  • The main characters in Leverage all eventually find out, but we the audience are never told what Sophie's real name is.

  • In the comedy song "The Homecoming Queen's Got A Gun", we'll never know who Johnny was, because only Debbie knew and, like, she's dead.
  • Carly Simon's famous "You're So Vain." Exactly who the song is about is still unknown, though Dick Ebersol, president of NBC Sports, won the right to know the secret at an auction. Various, largely conflicting clues have been released over the years. This has been explained by the song actually referring to about 3 different men.
    • Although actor Warren Beatty, one of the possible subjects of the song, has declared that he does, in fact, think this song is about him.
  • The identity of rapper Captain Murphy. Theories range from another persona of Tyler the Creator to obscure cult act Zeroh to singer Thundercat to experimental beatsmith Flying Lotus.
  • For much of the 1970s, there was speculation about blues/jazz singer Leon Redbone's true identity. He always performed in dark glasses and never took off his panama hat. He also had a big Groucho mustache. The most common story was that he was an alter-ego of Frank Zappa. Others held that he was another Andy Kaufman character. Given that he is still performing and both Zappa and Kaufman are dead.... or are they?
  • Ylvis's song "The Fox (What Does The Fox Say?)" poses but never answers the question, "What does the fox say?" This is a reference to how other animals have well-known onomatopoeic sounds ("Dog goes woof, cat goes meow, bird goes tweet, and mouse goes squeak...") but foxes don't. In Real Life, foxes make a variety of sounds, and words do exist for certain fox sounds, including "gekker" (for chattering) and "yiff" (for barks that foxes allegedly make while mating). Of course, the term "yiff" has a bad connotation after the Furry Fandom adopted it to mean furry porn.

     Newspaper Comics 
  • Calvin and Hobbes:
    • What was the Noodle Incident?
    • What is Calvin's family name?
    • What is the subject matter of Hamster Huey and the Gooey Kablooie?
    • What, precisely, is Hobbes—a stuffed animal or a living creature?
    • These are all questions that Bill Watterson has specifically refused to answer, either feeling the answers unimportant (as in the case with the characters' full names), or more satisfying if left up to the reader to decide (as is the case with Hobbes's true nature).
    • Calvin invokes it intentionally when he refuses to tell what he brought to "Show and Tell".
    It's a mystery that will haunt you all your miserable lives! You'll never, EVER know what I brought! You can beg and plead, but I'll never end your torment! I'll carry my secret to the grave! It's the show and tell that was never shown or told! (Evil Laugh)
  • What exactly did Sally Forth's husband do for a living? Even they aren't sure.
  • Peanuts:
    • Did Charlie Brown manage to kick the football for this one time?
    • What does the little red-haired girl look like?
  • When a Dilbert story arc involved the title character getting a girlfriend, the issue arose amongst the readers of whether Dilbert might actually "score" with her. Since sex wasn't something that could be openly discussed in a newspaper comic, Scott Adams told his readers that should Dilbert get lucky, his perpetually upturned tie would be drawn hanging flat. The flat tie strip did eventually come, but Adams still wrote the comic in such a way that it wasn't clear if Dilbert had had sex or not.
  • When Jon got stuck on a wall and asked for Garfield's help, he told Garfield not to ask how it happened.


    Religion and Mythology 
  • The Bible:
    • Where was Jesus and what was he doing between the ages of twelve and thirty-ish? The Gospel writers were not the least bit interested in even hinting at it (save for a glib, hasty note about him "growing in wisdom and spirit", which tells us nothing specific).
    • The pronunciation of the God of Israel's true name, YHWHnote , is unknown, as the Hebrew alphabet of the time did not include vowels. The most commonly used pronunciations are Yahweh and Jehovah. Jewish tradition forbids uttering the name of God, and the word Adonai is used instead. In English translations of the Christian Bible, YHWH is mostly replaced with lord, one of several translations for Adonai.
    • In John's gospel, what does Jesus write on the ground when he stops the stoning of the adulterous woman?
  • Norse Mythology:
    • What did Odin whisper to his late son Baldr's (the first Aesir ever to be Killed Off for Real) ear at his funeral?
    • Odin's two brothers, Vile/Honer and Ve, who helped him create the world and the creatures in it, simply disappear one day. Odin goes to great lengths to find the answer to their disappearance, finally sacrificing his one eye in the Well of Wisdom (as the eye can then see the past, present and future). Yet, he never tells a living soul the answer except his wife. He reasons that "What three know, the whole world knows."
    • When Baldr has been slain Odin rides to the death realm, overcoming many perils for twelve days in order to find him. Finally he meets an old witch. Having spoken with her Odin abandons his search and goes back to spend his days preparing for Ragnarok. He never reveals to anyone what the witch said.
  • Exactly what is the Sampo? (In the The Kalevala, it was interpreted as a mill that produced unlimited quantities of salt, flour, and gold, but this is just an addition of the 19th century compiler; the original tales do not actually say what Sampo is.)

     Stand Up Comedy 
  • In Joyce Grenfell's "Nursery School" routines, her Catch Phrase was "George, don't do that". We never learned what George was actually doing.

    Tabletop Games 
  • What are the Dark Powers of Ravenloft, and what are they up to? Word of God from TSR's writers and canon statements from Arthaus proclaim that this will never be revealed, and a novel that dared to try it was declared non-canon for doing so. Also, what actually happened when Strahd and Azalin found themselves in Mordentshire during their botched attempt to break out of the Land of Mists?
  • What is the Lady of Pain of Planescape?
  • Warhammer 40,000 is chock full of these. Some of the biggest are: What happened to the missing Primarchs? Is the Emperor truly alive or dead? What was the Pale Wasting?
  • Eberron has a number of these, added intentionally so that DMs have leeway to make stuff up while still sticking to the setting. Examples include: what actually triggered the Mourning, do the Sovereigns and Dark Six actually exist, and what are the long-term plans of enigmatic factions like the Lords of Dust, Inspired, and Chamber.
  • The GURPS setting GURPS IOU runs on this. IOU is Illuminati University... so what does the "O" stand for? Just who (or, for that matter, what) is the ArchDean anyway? Who is the Unseen Dean, and how many have they gone through? And what's the janitor's deal, anyhow? The answer to all these, and more, is frequently "You're not cleared for that." It even says so on the back cover.

  • In Waiting for Godot, who or what is Godot? Why are they waiting for him? Will he ever come? And just what on Earth was Lucky going on about?
  • Is it really the ghost of Hamlet's father, or just an evil spirit taking advantage of Claudius' crime to cause the prince even more misery? Or is Hamlet just crazy?

    Video Games 
  • Did Zelda actually change gender when she became Sheik, or did she just change her appearance? The general consensus (backed by the English versions of Super Smash Bros.. Melee and Brawl) is that Zelda's magic superficially affected parts of her appearance (clothes, eye color, and skin color), but fan debate continues to this day.
  • In the Super Mario Bros. games, just who is Bowser Jr.'s mother? Why did Bowser lie to him about it? Why does he keep kidnapping her if he knows she isn't his mother? Why didn't Princess Peach protest when he said that she was his mother?
  • Touhou has a crapload of this, probably as ZUN's way of encouraging fanwork. What happens if Rumia's ribbon is removed? What's the deal with Flandre's wings? What's Sakuya's backstory, and why was Eirin surprised to see her? Just how powerful would Alice be if she went all-out? What happened to Youki? Just how old is Eirin, anyway? What's Maribel's deal? Where exactly is Gensoukyounote ? How much of the PC-98 games are canon?
  • What is the name of the protagonist in Gothic? What was he imprisoned for?
  • Who exactly was the Head from the first Myth series game.
  • Pokémon: Just what the hell does the rest of Diglett and Dugtrio's bodies look like? And what do Cubone and Marowak's heads look like under the skull they wear?
    • Cubone's face has partially been revealed.
    • Fandom has stepped up to offer a few... ideas for Diglett and Dugtrio as well. They are not pretty.
    • What does the inside of a Pokeball look like to a captured Pokemon?
    • Where do Pokemon eggs come from? Despite the fact that you can leave Pokemon in daycares and they produce eggs. Nobody (not even the daycare staff) have seen Pokemon mate or lay eggs. They appear to simply poof into existence. This "mystery" might have been included to keep the games child-friendly.
    • What exactly turns a regular Carbink into a mythical Diancie? It is apparently a sudden mutation which is separate phenomenon from regular old evolution and the trigger is unknown. There's also no way to trigger this mutation in the games either.
  • In Planescape: Torment:
    • What did The Nameless One do that even a thousand lifetimes of good deeds wouldn't have been enough to atone for? For that matter, what is his name?
    • And what is it that can change the nature of a man?! Whatever you believe can change the nature of a man, can.
  • Will Shenmue ever be continued and Shenmue 2's massive game changing cliffhanger be answered?
  • Team Fortress 2. Who is the Pyro? What does he look like under his mask? What is he really saying? Is he really a woman? People held out hope that Meet the Pyro would explain everything, but Valve being Valve, they didn't.
    • Word of God amounts to "Leaving the question unanswered is funnier than any answer we can come up with now".
    • A meta-example: was Meet the Spy leaked by accident, or was it a publicity stunt? Valve recovered from it surprisingly quickly, for them, but they insist it was a mistake.
  • Yume Nikki: Whatever happened to Madotsuki in the past that caused her to become a shut-in, have horrific nightmares repeatedly, and ultimately commit suicide? The fact that everything in this game is ambiguous, lacking any sort of exposition whatsoever, makes this very question all the more important.
  • Escape Velocity Nova:
  • Games by Mateusz Skutnik tend to have these:
    • There are almost too many to count in Submachine. But probably the biggest are, what the hell is the submachine, and who is the player?
    • If it weren't for subtle hints of meaning throughout Daymare Town, it would just be a Mind Screw. Some questions are raised in-story (is it fog or mist surrounding the town?), others remain unspoken (how did the player get there?).
  • In Persona 4, a teenage girl strongly resents the department store she works at (for various social and cultural reasons). Her hatred of it is so great that it poisons her inner landscape and creates her Shadow, inadvertently causing her death...but she doesn't simply quit working there. We never find out why. At one point, she has a flashback to her father asking why she keeps that job- he suggests that maybe she wants the money from it, or that there's someone there she wants to spend time with- but her narration doesn't indicate whether any of these guesses are true.
  • In The Elder Scrolls, what happened to the Dwemer? All we know is that they did something with the heart of Lorkhan to try to become gods then all simultaneously disappeared in the middle of the first era (all the games take place in the second, third, and fourth eras). After four millennia in-universe, no one knows the answer, with the most popular theories being that they all died in the attempt, and they succeeded.

    Web Animation 
  • Homestar Runner: How do you type with boxing gloves on?
    • Similarly, any information about the parents of any of the main characters save for Pom Pom and Homsar. Except Homsar claims to be the son of a cup of coffee and a chipwich, which may or may not be true.
    • As well as what Strong Bad's face looks like without the mask. He does take off his mask once while obscured by a huge chair, then states that he will never do that again. The Brothers Chaps have stated they will likely never answer these questions.
  • How do the Happy Tree Friends keep coming back to life? The real answer obviously being Rule of Funny, but since it's left unexplained in-universe it still qualifies.

  • Bob and George - How did Metool-D2 end up in the Alternate Universe? The characters know, but the audience never will!
  • Shortpacked! contains a couple, the most glaring one being Galasso's resurrections of Ronald Reagan and Jesus Christ. Resurrection tech exists in the comic's universe, but it explicitly requires nine months to work (Mike showed up after being dead for five) and the subject's DNA (all of Mike's was destroyed), and it's also under government lock and key with an extensive waiting list. There's also the matter of the Drama Tag, the pulling of which may or may not have resulted in a Cosmic Retcon of Amber's childhood if it even exists at all.
  • Sluggy Freelance - "Who murdered Sherrif Deer?"
  • Homestuck devotes most of Arc 5 to introducing the trolls- an alien race from Alternia- and explaining how their Sburb session overlaps with that of the protagonists. However, the story makes it clear that the trolls are only deuteragonists at best, and many parts of their session are excised or heavily abridged, showing only the parts of it that are integral to Homestuck's Myth Arc. Therefore, fans are free to speculate on exactly what Alternian culture is like, and the trolls' lives before the game.
    • A specific example: What was that 'little moment' between Terezi and Karkat when she got close enough to learn his blood colour?
    • Where did Sburb really originate? Why does it even exist?
    • In-Universe example: The Ultimate Riddle.

    Web Video 
  • There's some random kid playing a video game in the Time... Lab during the Christmas episode of The Time... Guys. Knowing the showrunners, this will not go unexplained.

    Western Animation 
  • Avatar: The Last Airbender:
  • Used for a character but not the audience in the "Riddler's Reform" episode of Batman: The Animated Series. When Batman is able to escape The Riddler's deathtrap of sealing him in a building that has high explosives in it, the Riddler is so bewildered by Batman's escape that he no longer cares about going to Arkham or losing his now legitimate business and lifestyle and only cares about finding out how Batman was able to survive a trap he clearly shouldn't have been able to. While Bruce later explains it to Dick Grayson, and the audience, back at Wayne Manor, he never explains it to the Riddler himself. Mr. Nygma ends up going even more insane due to not getting an explanation.
  • The Emperor's New Groove:
    • This is pointed out when Yzma and Kronk manage to beat Kuzco and Pacha back to the castle, even after falling into a ravine.
    Kuzco: I don't believe it! How did you get back here before us?
    Yzma: ...How did we get here, Kronk?
    Kronk: (pulls out a map) You got me. By all accounts, it doesn't make sense.
    • Why did they even have that lever?
  • Jimmy Two-Shoes: Where did Jimmy come from? What is the nature of Miseryville? Is it really Hell? Is it just a hallucination of Jimmy's? Is he dreaming?
  • Phineas and Ferb:
    • In-Universe example—where exactly do their projects disappear to every day? They even try to work it out in the episode "Don't Even Blink", but (un)fortunately the Doof was working on an invisibility/destruct-inator that day, so they never found out.
    • What is the giant creepy floating baby head? Why does it keep showing up?
    • In a similar vein; the inexplicable talking Zebra that calls Candace 'Kevin'. Only Candace ever seems to see it, and it only appears when she's hallucinating, dreaming, thinks she's hallucinating or dreaming, or when ''somebody else is dreaming that she's dreaming''. That said, he also appeared in an parallel universe. Why can it talk? Why does it seem to known Candace? Why does it call her Kevin?
    • What is Ferb short for?
  • In The Simpsons:
    • One episode has Bart and Lisa escape from Mr. Burns by dropping down a laundry chute he's too big to fit into. But when they land in his mansion's basement, he's already waiting there with a gun.
    Bart: That's impossible! How did you get here first?
    Mr. Burns: Oh, there'll be plenty of time for explanations later.
    • In another episode, having forgotten his name, Grandpa checks his underwear. When asked how he removed them without removing his pants, he shudders and admits, "I don't know!"
    • In another episode Mr. Burns has gone to Scotland to capture the Loch Ness monster, which swallows him. The next scene shows the monster hanging tied up under Burns's helicopter on their way back to the States. Smithers is impressed that Mr. Burns could subdue the monster.
    Mr. Burns: Yes, I was a bit worried when he swallowed me, but ... you know the rest.
    • Why is Major League Baseball spying on us using satellites? More importantly, who cares? Mark McGwire is hitting some dingers!
    • In one episode, it seemed some Springfield Nuclear Power Plant employees would die of gas poisoning because the emergency exit door was just painted on the wall. Cut to the next scene with one of those employees at Mr. Burns' office asking for a real door and refusing to explain how he and the others escaped.
    • When Edna Krabappel first arrived in Springfield, Moe started dating her. Because she hated taverns, he pretended he wasn't a bartender. He then closed the bar and started tossing the patrons away. As he realized he kept retossing Barney, he asked how Barney came back in. Barney said that, as a drunkard, he doesn't know how he does most stuff he does.
    • Where is Springfield?
  • Sofia the First:
    • How can anyone's life be saved nine and a half times?
    • The episode "When You Wish Upon a Well" features a wishing well that grants Three Wishes. King Roland's first wish doesn't end well and this is all he says about that wish.
  • SpongeBob SquarePants: What is the secret formula of the Krabby Patty? And who was Pearl's mom?
  • In Teen Titans the episode "X" involved Red X (a supervillain identity Robin had previously invented as part of a Reverse Mole plan) showing up, with someone we can be pretty darn sure is not Robin under the signature Red X suit. Fans have wondered for some time who the new Red X really is, and Beast Boy came up with a number of theories, but Word of God says Raven came to the only conclusion that mattered:
    Raven: Face it, Red X could be anyone. Anyone smart enough to find the suit and dumb enough to take it for a joyride.
    • The most popular theory seems to be that he's Jason Todd, the second Robin.
    • In the New Teen Titans short Red X unmasked, Red X is captured, and unmasked, with Beast Boy insisting that he's Jason Todd. They unmask him to find it is Jason Todd, but that's also a mask, which they remove to find Speedy, who is also a mask, and they find New Fu, whom Best Boy eats and then they find Alfred, and then Batman masks, and then Silky, who really is just stuck in the suit, then a Larry mask, and then Slade, who's really an android who explodes. The real Red X tells them to keep guessing, with Beast Boy yelling that he still thinks he's Jason Todd.
    • The episode "Revved Up" revolved around Robin trying to get back a briefcase that Ding Dong Daddy had stolen from him. When asked what's inside it, Robin just says, "It's personal." When the briefcase is finally opened, its lid fills the entire screen, causing a Smash to Black, the end of the episode, and legions of fanboys/girls demanding to know, "What's in the frikkin' briefcase!!!" Possibly a Shout-Out to Pulp Fiction, where there was also a briefcase integral to the plot that we never find out the contents of.
  • The Venture Bros.:
    • What did Rusty Venture do to make the Monarch hate him so much? Lampshaded in one episode when Tim-Tom and Kevin question Dr. Girlfriend about it, only to realise they're not going to get a straight answer from her.
    • What was the purpose and function of the ORB? Who built it? Nobody knows and nobody ever will know now. The creators have admitted that they were basically trolling the viewers with this one and will probably never get around to answering it.
  • In My Little Pony: Friendship Is Magic, the Winged Unicorns Celestia and Luna are practically Physical Gods. Where do they come from?
  • The Secret Show: What's Changed Daily's original name and why did Lucy Woo believe it used to fit him?
  • Hey Arnold! has a couple, such as:
    • What was Arnold's last name? According to Word of God, it's "Shortman".
    • What was the identity and nature of the mysterious tenant Mr. Smith?
  • In Littlest Pet Shop (2012), it's never explained how Blythe's dumbwaiter accident gave her the ability to talk to animals. The most commonly accepted theory is that she bumped her head.
  • Archer: Who is Archer's father? The currently known candidates are Jakov, Len Traxler, and Ron Perlman.
  • Xavier: Renegade Angel: What the hell is Xavier? And how did two seemingly normal humans have one as a child?

    Real Life 
  • Some mathematical questions, like the Continuum hypothesis: does a set exist which is uncountable, but of a lesser cardinality than the set of real numbers? It turns out that either "yes" or "no" is consistent with the set theory axioms, as long as the set theory itself is consistent.
  • What came first: chicken or egg? More of an historical example since, as The Other Wiki points out, the riddle was basically solved once evolution became understood. The first chicken hatched from an egg that was laid by something that was almost, but not quite, a chicken. Therefore the egg came first. Note that dinosaurs, amphibians, and fish were laying eggs long before birds, let alone chickens, existed, as well.
  • Tons of unsolved crimes. Due to loss or degradation of whatever evidence once existed, Jack the Ripper's identity will probably never be known. Lizzie Borden's parents' killer was never convicted.
    • Who the heck was the Zodiac Killer, why did he do what he did, and what happened to him? Police may never be able to figure it out for sure. They've narrowed down about a dozen possible suspects recently, many of whom are already dead so even if they do solve this riddle, there's a good chance the killer will pull a Karma Houdini rendering the answer pointless for anything other than historical purposes.
    • Who was the Axeman of New Orleans, why did he target Italian-Americans, and why did he declare that he would spare those listening to jazz music?
  • Twenty-plus years after the fact, it seems unlikely we'll ever know the true nature or purpose of the man behind the Max Headroom broadcast intrusion. Although we may now have a lead...
  • Cracked has articles about The 5 Creepiest Unsolved Crimes and Unexplained Broadcasts.
  • Who was the Man in the Iron Mask, and what was the reason for his bizarre imprisonment?
  • One from the Wars of the Roses, what happened to the "Princes in the Tower"?
  • On October 3, 1849, Edgar Allan Poe was found wandering the streets of Baltimore in a state of delirium, wearing someone else's clothes. He was taken to a hospital and died four days later. He was never coherent long enough to offer any sort of explanation, and on the night before his death he called out the name "Reynolds." His death was attributed at the time to alcoholism, but his medical records have since been lost and no one is sure to this day what actually happened.
    • In the 1990s, a surgeon found a set of records that he eventually managed to identify as Poe's. He eventually identified the patient's condition (before realizing his identity) as rabies. Debate, however, still continues.
  • What, exactly, was written in the version of George Washington's will that the dying president insisted his wife burn, unopened, in his presence? Why did he write two, then choose to destroy one while on his deathbed?
  • What was discussed, and then erased, within "the eighteen-and-a-half minute gap" of the Watergate tapes?
  • The legendary Fermat's Last Theorem became such largely because Fermat wrote underneath it, "I have a marvelous proof for this theorem, but this margin is too small to contain it." It wasn't until decades after he made this note that, using massively powerful mathematics, someone actually managed to prove the theorem. Mathematicians continue to discuss whether Fermat actually had a proof, and if so, what it actually was.
  • Was Falco washingtonii, the eagle documented and named by John James Audubon, an actual species as he believed? As all alleged specimens have been lost or destroyed, it's unlikely we'll ever know if the raptor, which no other naturalist has ever documented, was an unusually-large juvenile bald eagle, a regional variation of the bald or golden eagle, a rare species that went extinct shortly after Audubon encountered one, or some sort of hybrid.
  • Pontius Pilate vanished from history after the trial of Jesus. There are several different stories about what happened to him later in life, but none of them are from credible sources and they all contradict each other.
  • Similar to the unresolved questions surrounding Edgar Allen Poe's death mentioned earlier, Walt Disney wrote the name of actor Kurt Russell, and nothing else, on a sheet of notepad paper while he was on his deathbed. It was known that Walt saw a lot of talent and potential in Russell, even to the point of seeing some of himself in the then-young actor. Just about everyone close enough to Walt to soundly judge the man's character also noted that Walt most probably had an idea he wanted to tell Kurt Russell all about in his final moments, although the possibility remains open that the request for Russell specifically had nothing to do with movies or any of the ideas Walt was playing with in his last days. What, exactly, Walt needed to talk to Kurt about is unknown, even to Kurt himself, as he went on record saying. The note, in the end, raised many questions that still haven't been answered nearly fifty years after Walt passed on, and probably never will be answered with anything resembling closure.
  • Who betrayed Anne Frank's family to the Germans?
  • Every single test to see how many licks it takes to get to the center of a Tootsie Pop has come up with a different answer. The world may really never know.
  • Albert Einstein's last words were in German. Too bad nobody around him at the time spoke German...
  • Nobody knows what happened to Anne Bonny after she wormed her way out of execution by pretending to be pregnant. Her partner-in-crime Mary Read is known to have died in prison, but Bonny just disappeared from the records. Some think she settled down with her lover and retired, others believe she continued pirating for the rest of her days.
  • What is the sound of one hand clapping?