History Main / TheFogOfAges

* In the ''Franchise/{{Transformers}}'' multiverse, Cybertronians may be an ''absurdly'' LongLived race of [[MechanicalLifeforms mechanical aliens]], but their recollection of their lifetime is far from perfect. They suffer a condition known as Information Creep: they gather so much information over their long lives that their brains slowly overwrite older, less important memories as they age to remain functional. Elder bots find that older events become more difficult to recall and details become less accurate as time goes on. Outside factors like mental activity, damage, and fuel levels can influence the severity of Information Creep, but it impacts them all if they live long enough. The reason their ancient history is typically lost to time despite having a few survivors of those ancient eras still around is that the memories those survivors have of their past have decayed into an unrecoverable state.
* Dojo of ''WesternAnimation/XiaolinShowdown'' helped Grand Master Dashi hide the Shen Gong Wu, but because he did it 1,500 years ago, he can't remember where he and Dashi put them exactly. Even if he did, the growth of civilization over all this time has rendered some of the original hiding places unrecognizable. To find them now, he has to rely on his SpiderSense to detect the magic the emitted when a dormant Shen Gong Wu randomly activates.

* The earliest known example of this in a video game is ''VideoGame/GloryOfHeraclesIII'', for the [[UsefulNotes/SuperNintendoEntertainmentSystem Super Famicom]], where the protagonist of the game is an immortal [[AmnesiacHero who suffers from amnesia]]. This plot element is used again in one of the sequels, ''VideoGame/GloryOfHeraclesDS'', where the protagonist is also an amnesiac immortal.

* In the second episode of ''Series/UrbanGothic'', vampire Rex (played by Keith-Lee Castle) admits that he can't remember how he became a vampire.

* Killy of ''Manga/{{BLAME}}!'' is a cyborg who has existed probably as long as the strange machine world of the manga. He is so old that he has forgotten even that he is a cyborg. At least, it seems so. It's hard to tell.
* Invoked in some ''Manga/{{Bleach}}'' {{Fanon}} to explain why Shinigami generally don't remember their mortal lives--they measure their ages in hundreds. In truth, most of them were never mortal to begin with--they were literally born in [[CelestialBureaucracy Soul Society]], putting them on a different level than humans. Still comes up in fanfic a lot despite WordOfGod.

* C.C. from ''Anime/CodeGeass'' suffers from this, [[spoiler: until Lelouch has a [[JourneyToTheCenterOfTheMind journey to the center of her mind]] and then Marianne returns all her memories.]]
* The Abh touch upon this in ''Literature/CrestOfTheStars'' and its sequels. They live for between 200 and 250 years and their genetic engineering technology is such that they can live ''much'' longer. It's not enough to stop The Fog of Ages setting in, though, so their bodies are designed to shut down while their mental faculties are more or less intact.

* In ''Literature/TheFamiliarOfZero'', Saito's trusty talking sword Derflinger has existed for over 6,000 years. He's very wise, but he has a lot of gaps in his memory.

* ''Webcomic/HetaliaAxisPowers'' has one in the video game ''VideoGame/HetaOni'', where Italy has so many memories of the time loops he starts to forget things from his real past.

* The manga ''Manga/{{Phoenix}}'' features a historical warlord who seeks to claim the blood of the eponymous bird, and with it, immortality, mainly so his empire won't fall into the hands of his incompetent sons. He decides against this when he gets a glimpse of himself in the future, practically invalid and bound to a machine that erases his memories so he has enough brainpower to function.
* In the ''Manga/SamuraiDeeperKyo'' manga, this is the StartOfDarkness of MagnificentBastard Chinmei.

* In the run of ''ComicBook/ActionComics'' starring ''ComicBook/{{Deadman}}, a ghost called Tlaloc becomes convinced he's a god after spending centuries trapped within a sacred pyramid. Deadman recognizes that they're the same and has to appeal to his human longings to stir Tlaloc's buried memories of his mortal life.

* An issue that explores all the backstories of the secondary characters in ''ComicBook/{{Invincible}}'' reveals that The Immortal has forgotten most of his life prior to becoming a superhero. Including being ''[[JuliusBeethovenDaVinci Abraham Lincoln]]''.
* ''ComicBook/LegendsOfTheDeadEarth'': In ''ComicBook/LegionOfSuperHeroes'' Annual #7, Wildfire can remember his exploits with the original Legion of Super-Heroes in the 30th Century after 4,500 years. However, with the passage of time, he has forgotten his real name, Drake Burroughs, and most other details of his life. The Legionnaire Membrain helps him to recover his memory through sensory deprivation.

* Det. Christian Walker, the main character of ''ComicBook/{{Powers}}'', is actually an [[{{Immortality}} immortal]] who's been around since caveman days. His memory seems to stretch back only about as long as a normal human lifespan, so in the present-day of the series he can only clearly remember from about the mid-20th century to the present. He does have vague recollections of the time before that, but those memories are as undefined as an old man remembering his childhood. His ArchNemesis[=/=]EvilCounterpart, on the other hand, seems to remember most of their history together. However, at the final tragic confrontation between the two, Walker demands to know why the nemesis has done the things he's done, and why the two have been fighting all this time. His enemy pauses then admits that even he can't remember anymore.

* In ''[[ComicBook/TheMultiversity Society of Super-Heroes: Conquerors of the Counter-World #1]]'', Immortal Man notes he's forgotten his own name over the ages. It's not stated if his EvilCounterpart, Vandal Savage, has the same problem.

* In an early ComicBook/PostCrisis story, [[Characters/DCComicsVandalSavage Vandal Savage]] laments how much advanced medical knowledge (from forgotten civilizations he used to rule) he has lost over the ages. When a modern geneticist hesitates in assisting him with some human testing, he bellows that he has 'forgotten more than you'll ever learn!'

* ''ComicBook/WonderWoman'': This is an admitted issue for Olympians and other such long lived individuals in volumes [[ComicBook/WonderWoman1942 1]], [[ComicBook/WonderWoman1987 2]], [[ComicBook/WonderWoman2006 3]], [[ComicBook/WonderWomanRebirth 5]] and ''ComicBook/WonderWomanOdyssey'', with Mars/Ares and Venus/Aphrodite being mostly nonchalant about it and the fact that they have drastically changed over time and Zeus violently refusing to acknowledge it even when he's lost track of his aspects.

* In the ''Manga/{{Bleach}}''[=/=]''Literature/TheFamiliarOfZero'' crossover ''[[http://www.fanfiction.net/s/7263810/1/The-Left-Hand-of-the-Death-God The Left Hand of the Death God]]'', Ichigo Kurosaki was betrayed by Soul Society and thrown into a dungeon to rot. By the time Louise inadvertently frees him by summoning him as her familiar, he doesn't remember how long he's been in there (he speculates he could have been imprisoned for decades or even centuries). He cannot remember his friends and loved ones' names, but he remembers their faces and what they were like, referring to Uryu as the Archer, Chad as the Giant, Orihime as the Healer, and Rukia as the Dancer.

* ''Fanfic/TheBridge'':
** Princess Luna's earliest memory is a sweet gentle voice who may or may not be her mother. The next is of her and Celestia as children being found and raised by a foster family. [[spoiler:This is because they don't have parents. They were newly created by Harmony when they were found. So in reality, she has NoInfantileAmnesia.]]
** In Monster X's heartbreaking backstory, his masters put him in cold storage until he is needed. Unable to break free, he starts repeating his name and the name of his wife and parents over and over again in an attempt to not forget but fails.
* ''Fanfic/TheLunarGuardsman'': Raegdan, the lone human in the story, has fallen victim to this. He has forgotten most of his life through the rifts (as he called them it was all too similar), and many other things, including his own name as there hadn't been anyone to call him by it for so long that it's completely gone for him now.
* PlayedForLaughs in ''WebVideo/FalloutNukaBreak''. Ben, a ghoul, has trouble remembering things from before the bombs fell over 200 years ago. One thing that does stick in his mind, however, is "[[EarWorm By Mennen!]]" [[spoiler:Takes a much less humorous turn when it's revealed that Ben is approaching old age for a ghoul and is starting to turn feral]].

* Louis in ''Film/InterviewWithTheVampire'' laments that he can remember the last sunrise he ever saw on the day he was turned in all its vivid detail, but can't seem to remember any sunrise before it.
* Despite being the provider of the page quote, Gollum from ''Film/TheLordOfTheRings'' is actually an aversion. Deep down he did remember his past life and his name. But during the centuries he held the One Ring, he just didn't ''care''.
* ''Film/HeNeverDied'': [[spoiler:Jack doesn't remember a lot of his life. He can't recall how old he is or remember his parents. Being Cain, however, he does remember murdering Abel]].
* ''Film/BloodOfTheTribades'': The vampires get this (it's even referred to as "the fog"), having great difficulty remembering things which took place long ago. Due to this, they've forgotten what their original religious doctrines were, allowing it to get corrupted over time.
* ''Film/TheOldGuard'': Andy is so old that she can't remember her own age, or what the members of her family looked like. Even her "real" name, Andromache the Scythian, reflects this. She was already thousands of years old by the time the Scythians entered the historical record in the 8th century BC. The Scythian era is just the furthest back she can remember.
* ''Film/PalmSprings'': Niles has been stuck in a GroundhogDayLoop for ''years'', possibly decades, and thus is functionally immortal. He honestly has no idea how old he is, having long since given up trying to keep track. When Sarah meets him, he's forgotten certain things about his life before the loop, such as what he did for a living.

* ''Literature/DirkGentlysHolisticDetectiveAgency'': [[MeaningfulName Professor Urban Chronotis]] is an {{immortal|ity}} {{time travel}}er who is explicitly capable of remembering about as much as a normal human. He doesn't forget things in chronological order, though; he just gets very absent-minded. Notably, however, when asked who he was and how he became immortal, he frankly replies he doesn't know. He has evidence he's been Regius Professor of Chronology for about two hundred years, and he thinks he took it up after he retired, but he has no idea what he retired ''from''. What he ''does'' remember, for some reason, are earrings and smells.
* ''Literature/{{Evolution}}'': The replicator robots share their memories with each other through the generations, but over long spans of time these become increasingly less reliable. By the time of New Pangea, the replicator swarms scattered through the stars have long forgotten where they came from, and their collective memory eventually trails away into a vague emptiness.
* ''Literature/SecondApocalypse'': The Nonmen accepted immortality from the Inchoroi, but did not realize that their mortal brains would not be able to handle it. Thousands of years later, they all have a certain level of amnesia. Some of their number, called Erratics, have learned that they can only lock painful memories in their minds, so they go about murdering everyone they hold dear just so they can remember that the people existed at all.

* ''Literature/TheMadnessSeason'' has an [[EnergyBeings energy-based species]] of creatures which are virtually immortal with this problem, and which therefore prefer to live in [[TheSymbiote symbiotic relationship with physically bound creatures]].
* ''Literature/TimeEnoughForLove'': After over two millennia of existence, Lazarus Long comments: "I told you my memory was playing tricks. I've used Andy Libby's hypno-encyclopedic techniques -- and they're good -- and also learned tier storage for memory I didn't need every day, with keying words to let a tier cascade when I did need it, like a computer, and I have had my brain washed of useless memories several times in order to clear those file drawers for new data -- and still it's no good. Half the time I can't remember where I put the book I was reading the night before, then waste a morning looking for it -- before I remember that that book was one I was reading a century ago."
* ''Literature/HarryPotter'': Very old wizards like Dumbledore avoid this by storing important memories in an enchanted chalice called a Pensieve. Which is useful in other ways as well, such as making it possible to [[ExpositionBeam pass those memories on to other people as needed]].

* ''Literature/{{Strata}}'': Age appears infinitely extendable, and "memory surgery" prevents brain overload.

** In ''Literature/{{Pyramids}}'', the high priest Dios prevented himself from dying by reversing time by sleeping in a pyramid but mentions that the process doesn't preserve memory. Instead, he refers to the written history of the kingdom as his memory. As a result, [[spoiler:he can't escape a millennia-long StableTimeLoop. By the time it comes around again it's a surprise.]]
** A downplayed example in the Wizards series: It's suggested a couple of times that the reason the seventy-something Dean of Unseen University occasionally acts like a rebellous teenager is because he doesn't remember being a teenager the first time, and vaguely suspects he may have missed out on it altogether.
* ''Literature/RedMarsTrilogy'': Advances in medicine let people live to over 150, but their memories start showing significant deterioration. This is pretty much cured by a drug cocktail that apparently 'refreshes' the taker's memory, to the point where they have highly detailed recall of practically their entire lives.
* ''The Minotaur Takes A Cigarette Break'': The Minotaur is still alive today, five thousand years later. His days in the Labyrinth are very vague to him.
* A point of ''Literature/{{Glasshouse}}''. Immortality means that humans need to periodically erase their memories to make things more interesting. The protagonist has just done this when the book begins.

* ''Literature/ObservationOnTheSpot'': Explicitly ''averted''. Ectocs have a photographic memory and can easily remember anything that happened centuries ago, with them being made of {{Nanomachines}}. That's just another reason why [[WhoWantsToLiveForever there's just six of them left]].
* ''Literature/XeeleeSequence'': In ''Exultant'', Luru Parz is one of a group of immortals who have survived more than 20,000 years. She claims that they can remember events from throughout their lives, but no more or less clearly than a normal person. Sometimes, events may bring forth a distinct memory that hadn't been recalled in several thousand years. Even so, they must "edit" their memories, but it isn't explained how this is achieved.
* ''Literature/AFireUponTheDeep'': Peregrine Wrickwrackrum, a storyteller among the Tines (a pack of dog-like aliens who form a group mind) claims to have memories from his ancestors going back to the beginning of time but admits that after you go beyond a few hundred years you can't tell the difference between legend and memory.
* In Creator/PoulAnderson's ''World Without Stars'', Humanity has cracked the immortality problem, so that no one dies of old age anymore. Every century or so people have to have old, unwanted, memories wiped, in order to make room for new memories.
* Many of the beings from the far future in the novella ''Starplex'' suffer from this. A species known as the Ibs suffers from a related problem -- their natural cause of death by old age is that their memories began to overwrite their ''autonomic routines''. In this they are unlike most other sapients, who have problems with their cellular structure such as telomere shortening; the Ibs are noncellular. In fact, the protagonist meets [[spoiler:himself from eons in the future]], who has forgotten [[spoiler:his own middle name]].
* The eponymous character of ''The Vampire Tapestry'' loses his memory each time he passes into hibernation, and speculates that this is a defense mechanism against this trope. [[spoiler:At the end of the book, he realizes it's more likely to be a defense against his becoming emotionally attached to the humans he has to prey upon.]]
* Oddly, this trope seems to apply to Hazel-rah in the epilogue to ''Literature/WatershipDown'', in which the venerable Chief Rabbit can't recall if the adventures attributed to him in his youth were real or not. On the one hand, said adventures couldn't have happened so long ago by human standards; on the other, Hazel is implied to have vastly outlived what's normal for wild rabbits, suggesting that his lapine brain's memory capacity has indeed reached its limit.
* Lampshaded in "Letter To a Phoenix", a short story by Creator/FredricBrown which is told by a narrator who is 180,000 years old (he ages one day per 45 years). He states he doesn't remember his own name because he only has enough place in his head for the important facts -- and what could be less important than a 180,000-year-old name he changed about a thousand times already?

* "Literature/ZimaBlue" by Creator/AlastairReynolds focuses in part on Arthur Zima's quest to find out where his obsession with a particular shade of aquamarine comes from.
* ''Literature/TheSecretsOfTheImmortalNicholasFlamel''
** [[Literature/TheEpicOfGilgamesh Gilgamesh]] has this problem. He is the oldest immortal, the only being that is truly immortal, (Elders and other immortals can be killed in battle) and has gone insane because of it. He has tried to kill himself a few times; one attempt involved standing under the test of the first atomic bomb.
** Flamel himself suffers from this sometimes. He once forgot how to speak and write English.
* Khayman in ''Literature/QueenOfTheDamned'' suffers from this. As the third vampire ever in existence, he has spent the last 6000 years continuously active, alternatively losing and regaining his mind over the centuries, thus remembers little of his own life. It's been implied that during his periods of sanity, he engages in a game of manhunt with the Talamasca, who study the supernatural, while simultaneously writing many treaties on the origins of the vampire race as a ''member'' simply because [[RefugeInAudacity he likes to mess with them]]. Averted with his contemporary Maharet, who holds on to the memories because of her connection to the numerous descendants of her human daughter, but played straight with her twin sister Mekare, who has gone insane over the millennia.
* Vampires in ''Literature/TheTwilightSaga'' have PhotographicMemory; the catch is that this only applies to memories they form ''after'' becoming vampires. Memories of their human lives are subject to fading. Alice, notably, cannot remember ''anything'' from back when she was human.
* Addressed in the ''Literature/CommonwealthSaga'': rejuv (restores youth) and quick-grown clones (in the event the body actually dies) together make humans functionally immortal. Everyone has a computer core in their brain that among other things records their memories. This core is regularly backed up to a municipal database.

* "Shining Hawk" in "Literature/TheGnarlyMan" by Creator/LSpragueDeCamp is a Neanderthaler who got zapped by lightning and wound up not aging, or at least aging very slowly. When he's interviewed, he turns out to be less useful than hoped: he can remember the broad strokes pretty well, but he gets his times mixed up ("Let's see, most of the men in the crowd had beards, so that was 8th century, or was it 12th, there were a lot of beards then too..."). Also, it turns out that unless you're invulnerable as well as immortal, the best way to survive history is not to be present during any of the more exciting bits of it, so anything interesting enough to be worth writing down he probably wasn't around for.
* In the ''Literature/{{Deverry}}'' novels, this is mentioned as a problem for elves (And the immortal human magicians Nevyn and Aderyn) as they get into their fifth century. In the days when the elves lived in cities, they tended to live extremely ritualized lives purely to help people who faced this function. Once the cities were destroyed and they became nomads, they tended not to live as long, so this ceased to be so much of a problem.
* Discussed in ''Literature/LineOfDelirium''. [[TheEmperor Emperor Grey]] wonders how many memories his brain can store. He wonders if anyone ever told him and then supposes it's possible they did and he simply forgot. Since ResurrectiveImmortality is possible for the richest few percent in this world, all memories are recorded (via an implanted SubspaceAnsible) and stored in massive databanks to download into the mind of a newly cloned body whenever the previous one dies. Grey is one of the early adopters of [=aTan=] (number 89, actually). By the time the novels take place, he is over 200 years old.
* In ''Literature/TheSagaOfTheNobleDead'', the vampire Pawl a'Seatt is so old that many of his memories have faded, and he can barely recall anything at all about his early life or how he became a vampire.
* Averted in ''Literature/TheWorldAtTheEndOfTime'', as Wan-To can remember ''all'' its past life [[spoiler:near the end of the book; its unique pastime living inside a dead star in a moribund Universe. Later, in order to leave that star corpse, must destroy most of its memories as there's no energy to carry all of them]].
* ''Literature/MasqueradeOfTheRedDeath'': Both [=McCann=] and Alicia have problems with this. More accurately, the two incredibly ancient vampires they are linked to have problems with this and it bleeds over into their mortal avatars.
* ''{{Literature/Horseclans}}'': After a few centuries, the Undying in many cases forget their past.
* ''Literature/CaptainFrenchOrTheQuestForParadise'': Averted with Captain Graham French, who has very vivid memories of his life spanning 20,000 years, although, to be fair, thanks to TimeDilation, he's only [[TheAgeless 2000 years old]]. He not only remembers details of his own life but recalls details of planetary histories and great literary authors. True, there are some things he's a bit foggy on but no more than an ordinary person having trouble recalling some obscure event or detail. At the same time, he mentions to his wife that the model she befriended on Barsoom has already likely forgotten her (decades have already passed for the universe outside their ship).

* In ''Literature/MidnightAtTheWellOfSouls'', Nathan Brazil is centuries old but only has a normal human-sized memory and has forgotten a lot of things, including his origins. [[spoiler:When he reaches the Well of Souls, it turns out he's been there before, and the Well recognizes him and restores his old memories, including the memory of who he really is. Which he then proceeds to give several deliberately contradictory accounts of over the course of the series.]]
* "Literature/TheBicentennialMan": The [[ProtagonistTitle main character]] used to be an NDR-model robot, but he doesn't remember which model number. This forgetfulness was deliberate, as he could have remembered, but he was built two centuries ago and he prefers his InSeriesNickname, Andrew Martin.
* ''Literature/StarTrekImmortalCoil'': Ruk, an android who wasn't terribly smart to begin with, has spent 50,000 years waiting outside a bunker on Exo III. Unfortunately, he's forgotten just what he's supposed to be waiting ''for'', and just as he's on the verge of a breakthrough, a spaceship crashes nearby.
* ''Franchise/StarWarsLegends'': The loss of Leia's homeworld, family, and so many friends is painful decades after the destruction of Alderaan, but it's a slowly fading ache. However, it's averted in the case of her friend Winter, who remembers everything that she has learned or experienced over the years. It was said that for Winter the pain of Alderaan's destruction was a fresh wound even decades after the destruction as she remembered every detail of her home and family back on Alderaan.
* Wit, a recurring character in ''Literature/TheCosmere'', is one of the oldest characters in the setting, clocking at minimum [[TimeAbyss 7,000 years]]. The end of ''Literature/RhythmOfWar'' reveals that he stores his memories in [=BioChromatic=] Breath, [[spoiler:which is vulnerable to tampering by a sufficiently powerful being]].

* ''Wolf Who Rules'', the second book in the ''Literature/{{Tinker}}'' series, makes note that "Elves may live forever, but their memories do not." They have a special ritual they perform where they reflect on particularly important memories -- good or bad -- to keep them fresh through the ages.
* In ''Literature/HeraldsOfValdemar'', the character Need is an ancient spirit bound into an [[CoolSword unbreakable sword]] and probably is the oldest character in the setting who's not a god. Sometimes she's conscious, but she also spends decades or centuries at a stretch 'asleep', driving people to [[WeHelpTheHelpless her]] [[AlwaysSaveTheGirl own]] [[ChronicHeroSyndrome ends]] and remembering them as dreams. She shows Skif and Elspeth memories of her time in life and the moment she [[HeroicSacrifice put herself into the sword]], which they find to be ''so'' old that they're hard to understand, but she doesn't remember her living name. It seems it's still there in her memories, as she rediscovers it while sharing more with another character, she just doesn't retain conscious access to a lot of her own experiences.
* ''[[Creator/JoeHaldeman Camouflage]]'':
** The Changeling was originally an [[ShapeshifterLongevity immortal shapeshifting alien]] exploring the Earth several thousand years ago. However, after being separated from its vessel, it gradually forgot where the ship was and why it had come to Earth in the first place, gradually forgetting more over the centuries until it finally regressed to a near-animalistic intellect. By the start of the story, the Changeling's oldest memories concern the various sea creatures it impersonated, and it's not until it begins impersonating human beings that it finally regains its old intellect - though it takes decades before it finally remembers who it was.
** The Chameleon is another shapeshifting immortal alien, having arrived on the same ship as the Changeling. However, unlike its counterpart, it came ashore instead of remaining at sea: as such, though it gradually forgot in much the same way as the Changeling, it retained its intellect and became regarded as [[UndyingWarrior a war god]] by the humans it lived among.
* In ''Literature/TheShipWho'', [[ManInTheMachine shellpeople]] are LongLived, much more so than ordinary unshelled humans. They usually have [[BrainsAndBrawn ordinary human partners called 'brawns']] who are {{Handy Helper}}s and general companions, and ''as'' ordinary humans these [[MayflyDecemberFriendship only stay with them for so long]]. Carialle, reflecting on her current brawn, wonders if she'll remember him in three or four hundred years. Losing him is a painful prospect now. After the fact it might get ''more'' painful and she might not even ''want'' to remember him.

* ''Series/{{Highlander}}'':
** Methos, the legendary [[TheOlderImmortal Oldest Immortal]], tells [=MacLeod=] that he's over 5000 years old, then explains that's when he took his first head and "before that, it all starts to blur." Methos therefore has no idea ''how much'' over 5000 years old he is; for all he knows, he could've gone for thousands of years before killing another Immortal for the first time.
** In general this appears to be averted for Immortals, as they have an astounding recall of events that happened centuries or millennia ago, complete with holding grudges against other Immortals they've encountered. One episode, however, had a case [[RashomonStyle where two different Immortals present at the same event have very different memories of it]]. As the director points out in his commentary for the episode [[UnreliableNarrator this should throw a huge shadow of doubt]] over all flashbacks that we see Immortals having and which had always seemed absolutely reliable before.
* ''Series/{{Supernatural}}'':
** Death can't remember if he is as old as ''or older than'' {{God}}. God, apparently, doesn't know either.
** According to Ruby, most demons have forgotten that they were once human. The only demons known to have some memory of their human lives are Ruby, Crowley, and Belphegor.
* In ''Series/TheXFiles'' episode "[[Recap/TheXFilesS06E10Tithonus Tithonus]]", Scully and Mulder meet a man who became immortal many years ago by accident -- when the Reaper came for him, he managed to look away and the nurse at his bedside was taken instead. He spends his time tailing people he knows are about to die and taking their picture right as they're taken so maybe he can look at the Reaper and finally die himself. When Scully expresses confusion as to why he would want to die when he has infinite time to see the world and gain every piece of knowledge, he tells her that forty years ago he went to the city's public records office to try to find his dead wife's file -- he couldn't remember her name.

** WordOfGod has it that the Doctor can't remember their exact age anymore--the Ninth Doctor just settled on '900' and started counting from there. This made into the actual show in "The Day of the Doctor," where the War Doctor and his tenth and eleventh incarnations are stuck in the same cell:

** In "[[Recap/DoctorWhoS35E5TheGirlWhoDied The Girl who Died]]", the Doctor suddenly pierces through the fog of his fading memories and remembers where he got his face from--[[Recap/DoctorWhoS30E2TheFiresOfPompeii a man whose family he once saved 1100 years ago]].
** This seems to be why the Time Lords have the Matrix, which records all their knowledge.

* According to Seven of Nine from ''Series/StarTrekVoyager'', the Borg also suffer from this, as their memory from over 700 years ago is beginning to fragment.
* An episode of ''Curiosity'' featuring Adam Savage of ''Series/{{Mythbusters}}'' was depicted as a future autobiography he wrote at age 1000. Among the other technological interventions he'd used to prolong his lifespan, he [[BrainUploading linked his brain to a computer]] so he could use its memory banks to supplement his own overfilled storage capacity.
* Parodied on Canadian teen sitcom ''Series/MrYoung'' with Mrs. Byrne, who has a memory span of a few seconds due to having lived through an ice age.
* In ''{{Series/Lexx}}'', the episode [[MusicalEpisode "Brigadoom"]] revealed that this was what happened to the Brunnen-G after retreating behind a nigh-impregnable shield on Brunnis II and cracking the immortality problem. After enough time people couldn't remember what their jobs used to be, or even which of the other immortals used to be their family members (One exchange has a pair of men wondering which one of them is the father and which is the son). It's implied this contributed to their insular behaviour and eventual downfall.

* [[ImpliedTrope Implied]] in ''Series/{{Alphas}}'' about Stanton Parrish, who has a form of immortality. He records all his memories using an Alpha named Mitchell (long story short, Mitchell is sort of a living journal). It's suggested that he does this because he's lived so long that he can't hold onto all of his memories.
* ''Series/StarTrekTheOriginalSeries'': In "[[Recap/StarTrekS1E7WhatAreLittleGirlsMadeOf What Are Little Girls Made Of?]]", Ruk is an android who's spent 50,000 years on his own, and has forgotten what happened to the civilization that made him and his kind. A little prodding from Kirk gets him to remember; the androids turned on their creators in self-defense.

* ''TabletopGame/{{Spycraft}}'': The "World on Fire" campaign setting has the Immortals as one faction. They succumb to this--at least, the ones who don't die from 'live fast, die old'.

* ''TabletopGame/VampireTheRequiem'' is the TropeNamer. One side effect of torpor (the comatose state [[OurVampiresAreDifferent vampires]] experience when they run out of blood or are beaten into unconsciousness) is that, the longer the [[OurVampiresAreDifferent vampire]] sleeps, the more their memories shift. A two-week nap is no big problem, but if you're asleep for decades, trying to recall your own memories is like trying to remember details from a dream. A number of bloodlines put a spin on this basic concept:

** ''Immortal Sinners'', one of the Night Horrors books for Requiem, also shows the rare subversions-certain very old, very powerful vampires, called Methuselahs, have learned to cheat the Fog of Ages, meaning they remember everything they care to. The example still makes grandiose claims about who he is, but that's because he's a habitual liar and TheTrickster who mainly does things ForTheLulz (and his ''real'' origin story is still pretty unbelievable).

** Fairies in general, and Cirno specifically, fall into this category--as {{Anthropomorphic Personification}}s of nature, they are immortal to FromASingleCell levels for as long as their aspect of nature is powerful enough to support them. Individual fairies may well be TimeAbyss material, but because they are also permanently childish and simple-minded, they often forget everything that happened yesterday, much less a thousand years ago. Cirno, for example, can only vaguely remember the previous occurrence of the flowers' odd growth from ''Phantasmagoria Of Flower View'', only after being reminded a few times, and can't remember any of the details, but is fine with it, since she doesn't care, anyway. She simply wants to do what she always does--play, fly around, and pick fights to see if she'll win. Downplayed somewhat in that she's relatively young at less than a human's lifespan, as well as more intelligent than the average fairy. Simpler fairies have absolutely no sense of self-preservation whatsoever.

** Fujiwara no Mokou, an immortal, somewhat played this trope straight. In a supplementary material for a manga, it's explained that her rivalry with another immortal that's often thought to have driven her to take the immortality elixir wasn't actually her motive--she had forgotten about her by the time she was tasked to dispose of the elixir and was more interested in the prospect of, er, being immortal. Her rivalry is more out of a sense that she has something constant in her life, now.
* The Skeleton race from Kenshi have been around for thousands of years, seeing the rise and fall of two empires before the events of the post-apocalyptic world the game takes place in. Most of the skeletons have all but forgotten their origins, and any questions about their origins and history is usually met with lack of recollection. It's rumoured in the human populations they were the cause of the apocalypse, and [[FakingAmnesia may be merely faking forgetfulness]] out of guilt or fear of being hunted down, although there are Skeletons who seem genuinely demented by their great age (such as the Armor King).
* ''VideoGame/LostOdyssey''.
** The main character is an amnesiac immortal who's lived for a thousand years; most of his memories are recalled through dreams as the game progresses. It's not a natural side effect of the immortality, though, but rather a case of LaserGuidedAmnesia that makes him more easy to manipulate.
* In ''VideoGame/PlanescapeTorment'', this is implied to have happened to Ravel Puzzlewell -- she's certainly not 'all there' when you meet her. As for The Nameless One himself, he is immune to this trope: He ''does'' suffer heavily from memory loss, but it's caused by him repeatedly dying and coming back instead of from living too long.
** According to Creator/ChrisAvellone, Ravel's apparent senility actually stems from the fact that due to her nature and having all of her "branches" (including Mebbeth, Marta and Ei-Veine), she sees across many planes and time periods all at once and she sometimes has trouble distinguishing exactly where or when she is (hence some of the strange dialog--it was meant to be spoken by another one of Ravel's "selves").
-->I have forgotten more of the Art than you shall ''ever know''.
** Another character does in fact keep journals; when that character experiences amnesia, the journals prove to be very helpful.
* In ''VideoGame/The7thSaga'', the robot Lux was built with a finite amount of memory and as a result has forgotten who built him and why.
* This is one of the defining setting traits of ''VideoGame/IMissTheSunrise''. With virtually everyone capable of living indefinitely, no one remembers more than a small portion of their life at any one time. An incredibly powerful {{Megacorp}} has arisen to store memories that would otherwise be erased over, which can be retrieved later should they turn out to be important. (This can be problematic if you've got memories you'd rather keep said {{Megacorp}} from gaining access to.)
* In ''VideoGame/EpicBattleFantasy'' ''3'', [[EldritchAbomination Akron]] has existed for so long that he doesn't remember when or how he came into being in the first place. He can still remember some things, such as being sealed, defeated, and released countless times by different heroes throughout the ages.
* In ''Videogame/DarkSoulsII'', this is one of the symptoms of the Undead Curse. The longer a person is Undead, the more their memories and sanity fade away. Human Effigies can temporarily halt this, but it still seems inevitable. One of them, Lucatiel, begs the Bearer of the Curse to remember her name, as she's forgetting it herself. ''VideoGame/DarkSoulsIII'' reveals the Bearer kept their promise by naming a hat-and-mask set Lucatiel's Mask, which still carries her name centuries after ''II''.
* ''VideoGame/DarkSoulsIII'': The DLC ''The Ringed City'' has Lapp, an Undead who claims to have lived for millennia, but is so old that Purging Stones (which usually help restore fading memories) no longer work on him, and as such he cannot remember his past. [[spoiler:He's telling the truth - as a matter of fact, he's [[RecurringTraveler Patches]], meaning he's lived since the first game, uncountable ages ago.]]
* In the ''Far Harbor'' DLC for ''VideoGame/{{Fallout 4}}'', the synth [=DiMA=] has been around since he was first created by the Institute decades ago. To help him remember more, he had his fellow synths install additional memory in him, although one of his assistants notes that the upgrades are approaching the limits of what his battery can accommodate. [=DiMA=] suggests that this is the reason [[spoiler:his "brother" Nick Valentine doesn't remember him, since it's been a long time since they escaped the Institute and Nick hasn't had the same upgrades to his memory]]. Even with the memory upgrades, he's had to offload some of his memories to a computer system in an old submarine base, guarded by the Children of Atom as part of his deal with them. [[spoiler:As it turns out, another reason's he's offloaded some of his memories is because he doesn't want to remember all the shameful, horrible things he's done to keep the peace on the Island, such as murdering the original Captain Avery and [[KillAndReplace replacing her]] with a synth]].
* The pros and cons of this trope are discussed at various points in ''VideoGame/XenobladeChronicles2'' and its expansion ''Torna: The Golden Country''. Pyra and Mythra, as the Aegis, hate the fact they must remember the destruction of Torna after 500 years, and at one point subtly express envy that other blades lose their memories when they "die" and are bonded with a new driver. Brighid, by contrast, keeps a diary in each of her "lives" so that she can keep the memories of her past in some form, which is made easier since she's an heirloom blade of a single royal family. And then there's Poppi, the artificial blade, who at one point suffers some minor angst when she realizes she's going to outlive most of her loved ones, but takes comfort in knowing her computer brain will never forget them.
* In ''VideoGame/XenobladeChronicles3'', [[TokenHeroicOrc Triton]] had already been getting on in years when he first joined up with Moebius, which granted him immortality. He's a scatterbrained sort, noting that entire lifetimes practically pass him by when he blinks. He has forgotten things such as how to transform into his Moebius form, and a promise he had made to an old friend with whom he travelled to [[spoiler:find the best recipe for the miso paste for which said friend had ''sacrificed his life to obtain''.]]

* In the ''VideoGame/GalaxyAngel'' gameverse, Moon Goddess Shatoyan has kept herself alive for over six hundred years [[BodyBackupDrive through a complicated cloning process]]. As a result, she has forgotten many of the secrets of the White Moon, including its true purpose in merging with the Black Moon and the existence of the Valfask race.

[[folder:Web Comics]]
* Immortals in ''Webcomic/ElGoonishShive'' have this as inherent to their nature, with a slight variation. Every couple of centuries, they "die" and [[LossOfIdentity lose the vast majority of their memory]] and power. They can apparently choose the time of their death, or even postpone it indefinitely, but this has [[WithGreatPowerComesGreatInsanity exactly the result you'd expect]]. Just before they "die", they can also "record" important memories and knowledge that their next incarnation will be able to access at will, but this is compared to recalling information read from a book rather than remembering something they had personally experienced. Pandora [[spoiler: having resisted doing so for centuries, attempted to "reset" ''without'' losing the connection to her family, but it remains to be seen how successful she was.]]

** The Bradicor [[http://www.schlockmercenary.com/2007-09-02 intentionally designed their own brains to work this way]]. Their normal brains couldn't handle becoming functionally immortal due to problems with long-term/short-term memory storage, but their new brains can... If only by intentionally 'compressing' long-term information to the point where they suffer from this trope. [[AxCrazy It beats the alternative.]]
*** Schlock himself is an evolutionary descendant of Branthicor brain material, with the same limits.

* A variation in ''Webcomic/{{Freefall}}'' where most of the robots have a "day memory" which starts to overwrite if they stay "awake" for too long. They must connect to a "dream machine" while they recharge in order to integrate important memories into permanent memory.
* Mammon from ''Webcomic/KillSixBillionDemons'' is an immortal dragon god who holds [[DragonHoard the largest hoard of money in the multiverse]]. [[spoiler:Unfortunately, his immortality [[AgeWithoutYouth has not protected him from the ravages of time]]; when the protagonists finally confront him, they find he's nearly blind and succumbing to dementia. He doesn't remember how or even ''why'' he collected his vast treasure and does nothing but shamble about aimlessly in his vault, counting all the gold in it. He's become such a pitiful, broken-down wreck that Allison [[SympathyForTheDevil visibly sympathizes with him]], despite all the pain he inflicted on others in his youth.]]
** Angels suffer a different version of this from their ResurrectiveImmortality. Each time an angel dies its soul crystallizes in the VoidBetweenTheWorlds until it is ready to be reborn, a process that lasts for about as long as the angel's last lifetime (as angels are TheAgeless, this means a dead angel can spend a ''long'' time between lives). Each death and rebirth costs an angel about nine tenths or so of their memories and experiences, meaning that by the time an angel has died ten times any memories left of their first life is probably extremely spotty at best. Angels like [[TheLancer 82 White Chain]] remember practically nothing of their origins, though their core personalty remains the same between incarnations.
* The multli-millennia-old Queen Albia in ''Webcomic/GirlGenius'' has a secret archive of memory, since it would be impossible even for her to store them all in her head. Interestingly, the archive is partially sentient and shifts between the personalities she had during those memories. [[spoiler:This bites her in the ass, because she had archived away an important memory from around 5,000 years prior which could have prevented the whole plot - specifically, the day her sister god-queens were slaughtered by a time-travelling Lucrezia]].

[[folder:Web Original]]
* In Website/OrionsArm this can easily happen to [[{{Muggles}} nearbaselines]] who live more than a few hundred years. Though cybernetic and [[NanoMachines nanotech]] enhancements to memory are usually widely available, it is still rare to live longer than about 1,500 years without [[BrainUploading trans]][[AscendToAHigherPlaneOfExistence cending]].
* [[http://www.furaffinity.net/user/-three-/ Three]] (aka [[IHaveManyNames Clarion, Silver, Assistant...]]) has been jumping from universe to universe for about 30-50,000 years, give or take. She can't remember exactly how old she is. She's also forgotten what her species or homeworld was called and possibly even her original name. She does try to hold on to certain memories, particularly those of close friends, lovers, and adopted children.
* In WebVideo/TheNostalgiaCritic, according to Rob, Santa Christ's age is around 2000 but he started losing his memory at 1200.

* Paradox from ''WesternAnimation/Ben10AlienForce'' is so old, he can't remember his own name, hence he adopts the moniker.
** He also had a [[BoredWithInsanity small bout of insanity]], which couldn't have helped. The fact that he exists outside of linear time probably doesn't help either.
** However, he does remember the details of the experiment that led to his immortality and even the name of his assistant.

--> ''This magic keeps me alive/ but it's making me crazy/ and I need to save you/ but who's going to save me?''
* [[spoiler:[[GreaterScopeVillain Horde Prime]]]] of ''WesternAnimation/SheRaAndThePrincessesOfPower'' has lived for such a long time that he has trouble remembering it all. When he needs to recall details about a bygone era--such as the days of [[AbusivePrecursors the First Ones]]--he has to access the memories of his [[BodySurf former vessels]] from their preserved bodies.
* In the [[Franchise/{{Transformers}} Transformers multiverse]], Cybertronians may be an ''absurdly'' LongLived race of [[MechanicalLifeforms mechanical aliens]], but their recollection of their lifetime is far from perfect. They suffer a condition known as Information Creep: they gather so much information over their long lives that their brains slowly overwrite older, less important memories as they age to remain functional. Elder bots find that older events become more difficult to recall and details become less accurate as time goes on. Outside factors like mental activity, damage, and fuel levels can influence the severity of Information Creep, but it impacts them all if they live long enough. The reason their ancient history is typically lost to time despite having a few survivors of those ancient eras still around is that the memories those survivors have of their past have decayed into an unrecoverable state.

* If you have a set MorningRoutine, your memory of individual tasks may fall prey to this--did you feed the cat this morning, or were you just remembering doing it a few days ago?
* The human brain can't remember everything that it experiences even within a standard lifetime. We all remember the significant moments of happiness, sadness, anger, etc in our life and significant events, but we usually don't remember specifically where we were or what we were doing on one arbitrary day half a lifetime ago. In fact, people who do remember everything in their lives in exceptional detail are often sufferers of brain disorders or dysfunctions which affect them severely to the point where their other cognitive functions are diminished and they are rarely capable of leading normal lives without assistance.

* In the [[Franchise/{{Transformers}} Transformers multiverse]], Cybertronians may be an ''absurdly'' LongLived race of [[MechanicalLifeforms mechanical aliens]], but their recollection of their lifetime is far from perfect. They suffer a condition known as Information Creep: they gather so much information over their long lives that their brains slowly overwrite older, less important memories as they age to remain functional. Elder bots find that recalling details of older events becomes more and more difficult and less accurate as time goes on. Outside factors like mental activity, damage, and fuel levels can influence the severity of Information Creep, but it impacts them all if they live long enough. The reason their ancient history is typically lost to time despite having a few survivors of those ancient eras still around is that the memories those survivors have of those days have decayed into an unrecoverable state.
* Dojo of ''WesternAnimation/XiaolinShowdown'' helped Grand Master Dashi hide the Shen Gong Wu, but because he did it 1,500 years ago, he can't remember where he and Dashi put them exactly. Even if he did, the growth of civilization over all this time has rendered some of the original hiding places unrecognizable. To find them now, he has to rely on his SpiderSense to the detect magic of the Shen Gong Wu emits whenever they randomly activate on their own.

* ''Literature/DirkGentlysHolisticDetectiveAgency'': [[MeaningfulName Professor Urban Chronotis]] is an {{immortal|ity}} {{time travel}}er who is explicitly capable of remembering about as much as a normal human. He doesn't forget things in chronological order, though; he just gets very absent-minded. Notably, however, when asked who he was and how he became immortal, he frankly replies he doesn't know. He has evidence he's been Regius Professor of Chronology for about two hundred years, and he thinks he took it up after he retired, but he has no idea what he retired ''from''.

* ''Literature/DirkGentlysHolisticDetectiveAgency'': [[MeaningfulName Professor Urban Chronotis]] is an {{immortal|ity}} {{time travel}}er who is explicitly capable of remembering about as much as a normal human. He doesn't forget things in chronological order, though; he just gets very absent-minded.

** Then there's Eina-Afa, a super-AI in charge of a space station the size of a large planet, who has been alone for longer than Earth has existed as a physical object.

** The Branthicor [[http://www.schlockmercenary.com/2007-09-02 intentionally designed their own brains to work this way]]. Their normal brains couldn't handle becoming functionally immortal due to problems with long-term/short-term memory storage, but their new brains can... If only by intentionally 'compressing' long-term information to the point where they suffer from this trope. [[AxCrazy It beats the alternative.]]

* In ''Literature/TheShipWho'', [[ManInTheMachine shellpeople]] are LongLived, much more so than ordinary unshelled humans. They usually have [[BrainsAndBrawn ordinary human partners called 'brawns']] who are {{Handy Helper}}s and general companions, and ''as'' ordinary humans these [[MayflyDecemberFriendship only stay with them for so long]]. Carialle, reflecting on her current brawn, wonders if she'll remember him in three or four hundred years. Losing him is a painful prospect now. After the face it might get ''more'' painful and she might not even ''want'' to remember him.

A common downplay is to have the immortal's friends and family be the only thing they still can remember. The tragedies, the wonderful days, the good times and the bad may all blur together after a while, [[{{Tearjerker}} but they]] [[BittersweetEnding can still]] [[SugarWiki/HeartwarmingMoments remember those faces.]] In these cases, the memories of those people might be the only thing that holds the immortal together, as those memories are the one thing they can anchor their mind to, and without them, they would forget who they are and who they were.

* In ''Literature/HeraldsOfValdemar'', the character Need is an ancient spirit bound into an [[CoolSword unbreakable sword]] and probably is the oldest character in the setting who's not a god. Sometimes she's conscious, but she also spends decades or centuries at a stretch 'asleep', driving people to [[WeHelpTheHelpless her]] [[AlwaysSaveTheGirl own]] [[ChronicHeroSyndrome ends]] and remembering them as dreams. She shows Skif and Elspeth memories of her time in life and the moment she [[HeroicSacrifice put herself into the sword]], which they find to be ''so'' old that they're hard to understand, but she doesn't remember her old name. It seems it's still there in her memories, as she rediscovers it while sharing more with another character, she just doesn't retain conscious access to a lot of her own experiences.

* Invoked in some ''Manga/{{Bleach}}'' {{Fanon}} to explain why Shinigami generally don't remember their mortal lives--they measure their ages in hundreds. In truth, most of them were never mortal to begin with--they were literally born in [[CelestialBureaucracy Soul Society]], putting them on a different level than humans. Still comes up in fanfic a lot despite WordOfGod.

* C.C. from ''Anime/CodeGeass'' suffers from this, [[spoiler: until Lelouch has a [[JourneyToTheCenterOfTheMind journey to the center of her mind]] and then Marianne returns all her memories.]]

* ''Webcomic/HetaliaAxisPowers'' has one in the video game ''VideoGame/HetaOni'', where Italy has so many memories of the time loops he starts to forget things from his real past.
* In ''Literature/TheFamiliarOfZero'', Saito's trusty talking sword Derflinger has existed for over 6,000 years. He's very wise, but he has a lot of gaps in his memory.
* In ''Manga/DemonSlayerKimetsuNoYaiba'', Kokushibo, the most powerful demon serving Muzan and one of the oldest demons in the setting, is one of the few demons who remembers his life as a human. However, it's been so long that he's forgotten the faces of everyone in his family, from his parents to his wife and child, with the sole exception of [[spoiler:his twin brother Yoriichi]].
* In ''Manga/OnePiece'', the giant warriors Dorry and Broggy have been fighting an endless series of duels for 100 years, getting draws each time, over a disagreement they had in the past. By the present, they have long since forgotten why they fight, only keeping at it for the sake of honor.

* Averted in ''Literature/TheWorldAtTheEndOfTime'', as Wan-To can remember ''all'' its past life [[spoiler:near the end of the book it's its unique pastime living inside a dead star in a moribund Universe. Later, in order to leave that star corpse, must destroy most of its memories as there's no energy to carry all of them]].

* In the [[Franchise/{{Transformers}} Transformers multiverse]], Cybertronians may be an ''absurdly'' LongLived race of [[MechanicalLifeforms mechanical aliens]], but their recollection of their lifetime is far from perfect. They suffer a condition known as Information Creep: they gather so much information over their long lives that their brains slowly overwrite older, less important memories as they age to remain functional. Elder bots find that recalling details of older events becomes more and more difficult and less accurate as time goes on. Outside factors like mental activity, damage, and fuel levels can influence the severity of Information Creep, but it impacts them all if they live long enough. The reason their ancient history is typically lost to time despite having survivors of those ancient eras still around, their memories of those days have decayed into an unrecoverable state or been forgotten entirely.
* Dojo of ''WesternAnimation/XiaolinShowdown'' helped Grand Master Dashi hide the Shen Gong Wu, but because he did it 1,500 years ago, he can't remember where they are exactly and has to rely on his SpiderSense to detect when they activate.

* [[Franchise/Transformers Cybertronians]] may be an ''absurdly'' LongLived race of [[MechanicalLifeforms mechanical aliens]], but their recollection of their lifetime is far from perfect. They suffer a condition known as Information Creep: they gather so much information over their long lives that their brains slowly overwrite older, less important memories as they age to remain functional. Elder bots find that recalling details of older events becomes more and more difficult and less accurate as time goes on. Outside factors like mental activity, damage, and fuel levels can influence the severity of Information Creep, but it impacts them all if they live long enough. The reason their ancient history is typically lost to time despite having survivors of those ancient eras still around, their memories of those days have decayed into an unrecoverable state or been forgotten entirely.

'''Eleventh Doctor:''' I don't know... I lose track. Twelve hundred and something unless I'm lying. I can't remember if I'm lying about my age, that's how old I am.

* In WebOriginal/OrionsArm this can easily happen to [[{{Muggles}} nearbaselines]] who live more than a few hundred years. Though cybernetic and [[NanoMachines nanotech]] enhancements to memory are usually widely available, it is still rare to live longer than about 1,500 years without [[BrainUploading trans]][[AscendToAHigherPlaneOfExistence cending]].