History Main / IdentityAmnesia

* ''Series/StarTrekStrangeNewWorlds'': In "[[Recap/StarTrekStrangeNewWorldsS2E04AmongTheLotusEaters Among the Lotus Eaters," the radiation on Rigel VII affects the brain by breaking down synaptic pathways, causing memories to fade away in about a day of being exposed. This is a result of an ancient collision of two moons that sent an asteroid to strike the planet, affecting the planet's climate and causing the native Kalar to be affected. The deep emotional memories and lifelong skills remain, but the rest is forgotten every night. [[spoiler:Yeoman Zac Nguyen ends up getting left behind on the planet during a mission and becomes king]] establishing a FantasticCasteSystem, according to which the Field Kalar (who do the manual labor) regularly lose their memories while the Palace Kalar don't, as [[spoiler:the palace walls and the guards' helmets shield their brains from the radiation]]. The Field Kalar have totems in their homes that tell the story of their people, as well as the legend that the Palace Kalar keep their memories because they're stored away in a casket at the palace ([[spoiler:Zac spread that myth intentionally]]). The effect of the radiation isn't permanent and can be counteracted by being away from the radiation or shielding from it. One elderly Kalar recovers all his memories after less than an hour [[spoiler:in the palace]]. When creamembers aboard the ''Enterprise'' start being affected by the radiation, Spock has Ortegas take the ship into the debris field, assuming the asteroids might shield the ship, unaware that it was the asteroids themselves that are causing it. In no time at all, everyone aboard loses their memories, and Spock's band-aid measure of handing out [=PADDs=] with personal files fails to help (even Spock is unable to read his own PADD, especially since it's not written in his native language). Luckily, [[spoiler:the ship's computer lets Ortegas know that she's the ship's pilot, and she's able to use her deeply-ingrained skills to fly the ''Enterprise'' out of the AsteroidThicket. After returning, Pike has the fallen asteroid lifted into orbit to allow the Kalar to recover their memories, ignoring Spock's protests about it violating the Prime Directive.]]

* ''Series/StarTrekStrangeNewWorlds'': In "[[Recap/StarTrekStrangeNewWorldsS2E04AmongTheLotusEaters Among the Lotus Eaters," the radiation on Rigel VII affects the brain by breaking down synaptic pathways, causing memories to fade away in about a day of being exposed. This is a result of an ancient collision of two moons that sent an asteroid to strike the planet, affecting the planet's climate and causing the native Kalar to be affected. The deep emotional memories and lifelong skills remain, but the rest is forgotten every night. [[spoiler:Yeoman Zac Nguyen ends up getting left behind on the planet during a mission and becomes king]] establishing a FantasticCasteSystem, according to which the Field Kalar (who do the manual labor) regularly lose their memories while the Palace Kalar don't, as [[spoiler:the palace walls and the guards' helmets shield their brains from the radiation]]. The Field Kalar have totems in their homes that tell the story of their people, as well as the legend that the Palace Kalar keep their memories because they're stored away in a casket at the palace ([[spoiler:Zac spread that myth intentionally]]). The effect of the radiation isn't permanent and can be counteracted by being away from the radiation or shielding from it. One elderly Kalar recovers all his memories after less than an hour [[spoiler:in the palace]]. When creamembers aboard the ''Enterprise'' start being affected by the radiation, Spock has Ortegas take the ship into the debris field, assuming the asteroids might shield the ship, unaware that it was the asteroids themselves that are causing it. In no time at all, everyone aboard loses their memories, and Spock's band-aid measure of handing out [=PADDs=] with personal files fails to help (even Spock is unable to read his own PADD, especially since it's not written in his native language). Luckily, [[spoiler:the ship's computer lets Ortegas know that she's the ship's pilot, and she's able to use her deeply-ingrained skills to fly the ''Enterprise'' out of the AsteroidThicket. [[spoiler:After returning, Pike has the fallen asteroid lifted into orbit to allow the Kalar to recover their memories, ignoring Spock's protests about it violating the Prime Directive.]]

* AlternateIdentityAmnesia - A character who shapeshifts or has a case of JekyllAndHyde has no memory of their actions while in their other form.

* Maze suffers from this at the start of ''Anime/MazeMegaburstSpace'', the only thing about her identity she remembers is the name Maze.

* Creator/SparkyLyle's ''Literature/TheYearIOwnedTheYankees'' had a player named Felipe Suarez who, after breaking a bat over his head, began to think he was Don Mattingly.

* ''LightNovel/ACertainMagicalIndex'': Kamijou Touma forgot a lot about who he was when he took a feather of St. George’s Sanctuary to the face and it is irrecoverable. He forgot a lot of people he knew; he forgot why he said people were indebted to him; school; he even forgot what his parents looked like, [[spoiler:which is aplot point]]. While a thank you letter had allowed him to obfuscate competence and convince everyone that he's fine, at least twice he had to gamble that he should have known someone because they [[HighlyConspicuousUniform dressed weirdly]]. [[spoiler:Eventually, he fesses up to someone about it.]]

* ''Anime/Golgo13''. In the anime series, Duke Togo has a loss of memory after a bomb explosion, and is aided by the requisite beautiful female bystander. Being TheDeterminator, even without knowing he's a ProfessionalKiller at first, Togo gathers enough information and fragments of memory to make it to the kill zone he's selected, but the question remains: who was he meant to kill among the people assembled in the kill zone? [[spoiler:Togo fires his gun in the air, and the hail of bullets from the bodyguards somehow restore his memories. Then he's faced with killing the woman who helped him, as he must LeaveNoWitnesses. A stray bullet however takes care of that problem.]]

* In ''[[Anime/MobileSuitGundam00 Gundam 00]]'', [[spoiler:Soma Peries]] experienced a rather complicated version of this. [[spoiler:She was originally Marie Parfacy, a kind-hearted girl who was a friend of Allelujah Haptism during their childhood until she was implanted with the Soma Peries personality. After the persona was implanted, she lost her memories as Marie and became]] a ruthless and fearless antagonist of the Human Reform League in Season 1 and then later, A-LAWS in Season 2. [[spoiler:Thanks to Allelujah, she regained her memories and returned to her former self and switched allegiances to Celestial Being later in Season 2. Both personalities coexisted until Sergei Smirnov (her commander who she views as a father figure throughout Season 1) was killed which led to Marie reverting back to Soma. After the final battle, Marie's personality returned and has remained dominate ever-since. The Soma persona only resurfaces for combat as Marie doesn't have the stomach for war.]]

* ''Anime/{{Patlabor}}'' has one of them with Ota who didn't remember anything after a big party and woke up with an terrible hangover not knowing who he is. Worse, [[spoiler: looking at the mayhem around him and his unconscious team-mate, he believes himself to be a murderer and runs away from every person who could have explained the jokes his friend played on him (in an attempt to make him avoid [[ViolenceIsTheOnlyOption unnecessary violence]]). As you can expect, after a really deep introspection, he will completely forget any lesson he could have learned during his amnesia when he wakes up at the hospital.]]

* In episode 16 of ''LightNovel/ScrappedPrincess'', Pacifica gets amnesia after being blasted out of the mobile fortress she was in, and spends most of that episode in town under the assumed name of "Pamela". She spends two more episodes like this, even insisting that her name is "Pamela" when her friends recognize her. She later regains her memory after being captured by Chris and later rescued again by Shannon, at which point she has no memories of her time as "Pamela".

* Tsukasa, the lead character of ''Anime/DotHackSign'' begins the show with this, with the added bonus of being stuck inside an MMO where he can feel everything. The adult friends he (eventually) makes do what they can outside the game to learn his identity. Parts of his memory comes back in pieces as the show goes on such as his mother's love for black and white era western films to a shopping mall he used to go to. But the final revelation (that Bear actually figures out relatively early in the show but Tsukasa initially rejects as impossible) is that [[spoiler:Tsukasa was actually a girl in real life and her father abused her for the crime of not being a boy.]]
* Sakura has this in ''Anime/ZombielandSaga'', even though none of the other zombies do. It is likely justified, though, by the means of her death; massive head trauma from being hit head-on by a speeding truck.

* In ''Film/{{Blackout}}'', Keith Carradine's character is in a car accident that leaves him an amnesiac and the other man who was in the car dead. As only one of the men's identities is known, Keith takes on that one, and becomes a sweet guy who marries his nurse, adopts her kids, and has a baby with her. Everything is going swimmingly until [[spoiler: everyone, including Keith, suddenly realizes he's actually the other guy - a crazed serial killer.]] Oops.

** An {{Elseworlds}} comic, ''Batman: Hollywood Knight'', has an actor who plays Batman (here a fictional character) in film serials barely surviving getting shot in the head by mobsters, only to start thinking he really ''is'' Batman and proceed to run around fighting crime.

* In the 2022 South Korean action movie ''Carter'', the title character wakes up in a bloodstained apartment, confronted by gun-toting CIA agents, with no idea who he is. He's suggested to be either a North Korean or CIA agent, but it takes him a while (and much asskicking) to find out which.

* AlternateIdentityAmnesia - A character who shapeshifts or has has a JekyllAndHyde no memory of their actions while in their other form.

* ''VideoGame/DivinityOriginalSinII'': {{Justified|Trope}} with Sebille, who is missing large chunks of who she was before she was enslaved with a magical RestrainingBolt, made into an assassin, and [[GirlInABox stored in a box]] between missions. If she's in the party, she rediscovers that she's [[spoiler:the Prime Scion, who will become a ruler over all elvendom.]]

* ''WesternAnimation/SpongeBobSquarePants'' episode "Squid Baby" has Squidward getting hit on the head (causing it to swell really big) and thinking he's a baby, who [=SpongeBob=] and Patrick need to take care of.
** [=SpongeBob=] himself gets a similar bonk in "Whatever Happened to [=Spongebob=]?" and somehow ends up as the mayor of New Kelp City (the undersea {{Expy}} of New York City). This is not necessarily a good thing.
** The episode "Mimic Madness" features [=SpongeBob=] doing imitations of everyone in Bikini Bottom so much that he develops "Mocking Mimicry Madness" and forgets who he really is.

* In the Creator/LaurelAndHardy film ''A Chump at Oxford'', it is revealed that Stan' regular foolish self is the product of amnesia - originally he was one "Lord Paddington", a prestigious Oxford University scholar who had lost his memory and wandered off after getting hit on the head by a closing window. Eventually Stan gets hit on the head in the same manner and regains this original intelligent, snobby personality, while accordingly losing all memory of his life as "Stan Laurel", essentially making this trope apply both ways. Naturally he later gets hit on the head again and returns to the "Stan" persona in the film's conclusion.

* After the Alpha [=AI=] from ''Machinima/RedVsBlue: Reconstruction'' severed its memories of torture from itself, it completely forgot what it was. Using the few memories it retained, it adopted the [[LivingMemory identity of a younger version]] of its [[BrainUploading creator]]: [[spoiler:Dr. Leonard Church]].

* ''Infinity'' series:
** ''VisualNovel/Ever17'': The Kid. [[spoiler:In an interesting use of this trope, the amnesia is used to hide the fact that there are two Kids. Both of them, Kaburaki and Hokuto, lose their memory due to being briefly possessed by a fourth-dimensional being.]]
** ''VisualNovel/Remember11'': Satoru suffers partial identity amnesia. [[spoiler:His past self was responsible for the FreakyFridayFlip that he is undergoing during the story.]]

* ''VideoGame/DeadOrAlive'': The second game features a character named Ein. He is a master of karate but he doesn't remember his true identity. [[spoiler:At the end of the second game, he is revealed to be Hayate.]]

* In ''Webcomic/TheSplatCrew'' comic "Rise of Darkness", Darkness, an [[VideoGame/{{Splatoon}} Inkling]] who is the SoleSurvivor of a beach raid caused by Octolings, completely forgets who she is after the event and decides to call herself Darkness after another Inkling says he likes how she has a kind of "darkness" to her.

* In ''WesternAnimation/ThePowerpuffGirls'' episode "Los Dos Mojos", Bubbles gets knocked on the head and thinks she is Mojo Jojo.

* In ''Film/{{Unknown 2011}}'', Liam Neeson's character awakens from a coma after a car accident only to find that no one, not even his wife, recognizes him. He then starts to question his true identity, yet as it turns out, [[spoiler: he's actually an assassin, and the person that he thinks he is is actually only the cover identity given to him for this particular mission.]]
** And in ''Film/{{Unknown 2006}}'', the entire cast awaken in a warehouse with no memory after they were exposed to a toxic gas. Figuring out who's who becomes a pressing matter when they discover that A) they're all locked inside, B) some of them are kidnappers who'd abducted the others, and C) the kidnappers' armed and ruthless accomplices will be arriving in a few hours.