Is there something that absolutely must be done for plot reasons, but the character that must do it has absolutely no obligation to do so? Sometimes a writer will write himself into a corner. The main character has to be in an abandoned field to meet the giant mutant insectoid elephants in the middle of the night, but there's absolutely no reason for her to be in that field at midnight.
Well, why can't she just know?
"I just knew" is an all-purpose plot contrivance for all a writer's needs, and can usually be explained away by the compelling forces of magic or psychic powers. When asked why a character had to be at a certain place or do something at a certain time, the response will always be, "I just knew." Unless there's a previously well-established reason for this character to be compelled as such, or careful, delicate mind-control is revealed later, this is a sign of lazy plotting. Usually it is in those cases, too.
Anime & Manga
- Princess Mononoke: "The head must be returned by human hands!" Did Ashitaka take Bizarre Supernatural Stuff That's Never Happened Before 101 at Exiled Prince University or what?
- In Marvel's Guardians of the Galaxy comics, the character of Starhawk referred to himself as "One who knows", using this as a rationale for suggesting courses of action that were often contrary to the team's current goals. Of course he'd turn out to be right. We find out later it's because he's stuck in a loop where his soul reincarnates into his own infant body, so he's lived through the events multiple times and simply remembers the correct path to take.
- Subversion: In the 2005 remake of The Cabinet of Dr. Caligari, this is one of the hero's most frequently used lines. It turns out that he's nuts.
- Played for Laughs in My Little Pony: Equestria Girls. Twilight Sparkle is about to explain everything to the alternate versions of her friends from Equestria, when Human!Pinkie Pie does it for her by blurting out a rapid-fire summation of the entire plot of the movie.
Twilight Sparkle: How did you know all that?!
Pinkie Pie: Just a hunch!
- In Transformers: The Movie, Hot Rod says he "just has this feeling" that the Autobot Matrix of Leadership will help them defeat Unicron. It does. Given that he'd briefly handled the Matrix when Optimus died and he was the one actually chosen to carry it, it had probably told him.
- Lampshaded in the film version of Harry Potter and the Half-Blood Princenote after Harry declares that Malfoy is a Death Eater.
McGonagall: That is a very serious accusation, Potter.Snape: Indeed. Your evidence?Harry: I just know.Snape: You just... know.
- As it turns out, Harry is completely right.
- Justified in Harry Potter and the Half-Blood Prince, where Harry drinks a Luck Potion, which grants him this ability.
- Cassie from Animorphs can see people's motivations and in the final arc she lets Tom get the Escafil Device out of instinct and is seen as a traitor. But it causes the Yeerk Empire to break apart because of the morphing power it grants is being denied to the taxxons and Tom uses it as a incentive to betray Visser One. She's not called Cassandra for nothing.
- Used by Richard, in Sword of Truth. Repeatedly. The most egregious instance is in Naked Empire, where he all-of-a-sudden knows the recipe for the antidote to the poison that's killing him, with no indication of how he knows it.
- Stephen King uses this one a lot in The Dark Tower series. Plenty of times, the heroes have vital information just suddenly pop into their heads out of nowhere. It's usually "explained" away as the doing of "Ka", fate. "Why can't we just go around Lud?" "Ka." "How do you know how to operate these magic doors?" "Ka." "How did you know to keep a hold of the crazy, stupid magic turtle?" "Ka." Partially justified because the protagonist has gone through the adventure thousands of times already, over and over, but still. Lazy.
- Mordred Deschain even wonders about how he knows this stuff once. Of course, he's born during the cycle, so he might well have learned some things other times around.
- Parodied and Lampshaded in Game Night by Jonny Nexus. One of the gods' mortals fell into a river, stranding him behind an impenetrable doorway the party had already passed, and the rest of the party had no way of knowing he was alive, let alone where he was. The other gods have their mortals go back and find him, and the mortals (who don't know they're literally the gods' playthings) comment on how strange it was that they were so compelled to return to the gate.
- Garion got this quite a bit in the course of The Belgariad.
- Justified, he was being guided by the prophecy.
- Justified for Saracen Rue in Skulduggery Pleasant, since he has an adept ability that grants him knowledge of things he shouldn't know about, but not other things. What exactly this power is and on what basis knowledge is granted to him is his most closely guarded secret.
- Subverted with Locke in the fifth season as he seems to intuitively know where to go and what to do, as if the island is guiding him, but it is actually because he's not Locke.
- Played straight with the Man In Black who possesses certain intuitive knowledge just because.
- Used well and thoroughly creepily for the villains in a first season episode of The X-Files, "Eve". The clone girls' coordination was spine-chilling.
- Used in the majority of The X-Files as Mulder always takes a wild stab in the dark at what the monster-of-the-week is based on little to no evidence, and is pretty much always correct. Except in the above Eve case, ironically enough.
- Used as a major plot point in the first season Christmas episode of Scrubs. Turk has been doubting his faith in God after working an on call shift on Christmas Eve (one of the worst nights to work such a shift), while Elliot has lost track of a scared pregnant woman. Turk, not having even met the woman, is sitting on the roof when suddenly he a realization hits him and he starts running to the park, where he finds the woman under a giant Christmas tree and helps to deliver the baby. When asked by Carla how he knew she was there, he answers: "I don't know, I just... knew." The implication is that God told him where to go, which is enough to restore his faith.
- In Phoenix Wright: Ace Attorney, witness April May "had a feeling" that she should look out her hotel window at a critical moment. She's lying - about looking out the window and, in fact, just about everything else - to frame the defendant and protect her employer, Redd White.
- Super Danganronpa 2: During the third case, Hajime is approached by someone who suggests he investigate the conference room at the hospital. Said location seems completely unrelated to the crime even after inspecting it, but it is crucial to solving the case, leaving the question of just why he was asked to investigate it. Since the one who approached him is eventually revealed to be sharing information with Monomi and is literally incapable of revealing this, the most likely explanation is that Monomi told them of the conference room's significance and approaching Hajime was a practical way of sharing this information.
- Justified and used as a major plot point in Zero Escape trilogy. Characters know things they shouldn't know because they have latent psychic powers. In fact activating and exploiting these powers in some way is a goal of each Zero.
- Parodied in a Running Gag AH.com: The Series, where (from the end of Season 4 onwards) Once an Episode the character Landshark will make a ridiculous (and accurate) leap of "deduction". When asked how on earth he knew that, he shrugs and replies "Hey, I'm British!"
- Constant in Dominic Deegan. Between the main character being a seer (who's in the business of doing this), his main method of saving the day being finding out what's going on and making sure the information gets to the right people if it takes psychic implantation, and Fate Itself and various other mighty forces weighing in periodically, this happens all the damn time. Occasionally it is wrong, or at least invokes From a Certain Point of View. Though not Dominic. Only his interpretations are ever off.
- Avatar: The Last Airbender: The third episode has Aang stating as much on identify a statue of his predecessor Roku, despite the statue not telling anyone who it is, and having no ability to call on any previous Avatars at that point.