Amnesia is a recurring plot device in the Final Fantasy series. The type of amnesia usually depicted is retrograde amnesia, where the afflicted loses their past memories but is able to function normally and retain new memories. Other than this however, the cause of the memory loss varies, but universally is used to conceal some secret about a character's past integral to the plot. How they recover their memories also varies.
In the 3D versions, Luneth, Arc, Refia and Ingus have forgotten they were born on the surface world and were brought to the floating continent and given to foster parents by Cid Haze. Desch lost his memories while being in suspended animation for a 1000 years. He doesn't regain his memory until the party reaches the Tower of Owen.
While sailing to Baron, Leviathan attacks the party's ship and Yang is washed overboard, awakening on the Baron shorelines without his memories and being appointed a captain of the guard due to his Monk training. When Cecil arrives in town Yang and his men attack him, and Cecil and his allies defeat Yang in battle, the blows restoring his memory.
Galuf suffers a blow to the head prior to meeting Lenna and Bartz, and loses all his memories save for his name. He recovers a bit of his memories but does not remember in full until his granddaughter Krile appears, the sight of her restoring his memory. Due to his injury Galuf feigns head trauma and swoons as a running gag when he acts questionably. When the party is confronted by Siren, she tries to lure Galuf with an image of Krile apparently pulled from his mind, but the attempt fails as Galuf's amnesia causes him to not recognize her.
Terra begins with no memories save for her name and a few brief recollections of the Gestahlian Empire, due to the Slave Crown used to control her mind distorting her thoughts. Once the magicite Maduin is brought to her, Terra's mind clears and she recovers her memories.
Gau's father has repressed the memories of Gau's birth, convincing himself he never had a wife or son in real life, and believes that in a dream he was married and lost his wife giving birth to a "demon child" he abandoned on the Veldt.
Cloud suffers from a complex series of memory disorders. After impressing Zack and Tifa's memories of him combined with his own ideal image of himself as a SOLDIER, much of Cloud's memories distort into a false reality where he joined SOLDIER and became Sephiroth's partner, forgetting Zack even existed. Cloud's memory remains full of inconsistencies and holes that he is unable to explain, and further toll on his identity is aggravated by Mako poisoning upon him being washed into the Lifestream. It is only after Tifa journeys into Cloud's Subconscious that the two of them can reconstruct Cloud's true memories and restore his mind.
Prolonged use of Guardian Forces results in memory loss due to the GF's presence in the controller's brain residing in the same areas that govern long-term memory. The party's loss of memory isn't revealed until Irvine tells Squall, Quistis, Zell and Selphie that the five of them, along with Seifer and Ellone, were orphaned and raised by Edea Kramer at a seaside orphanage.
As the five were sent to Gardens to train as SeeDs, they began to use GFs and forgot about their childhoods, Irvine remembering due to not using GFs until he met up with the party as he has never trained as a SeeD.
Garden Faculty is aware of the deleterious effect of the GF, but urge students to ignore any GF criticism they may hear from other forces. Quistis at first refuses to believe that Headmaster Cid Kramer would allow such a dangerous thing, but is forced to acknowledge the truth of the matter.
Both Zidane and Garnet have no memories of their early childhoods. Zidane was abandoned on Gaia by Kuja at an early stage of life, and remembers nothing of Terra save for a blue light. Garnet was born in Madain Sari as "Sarah", and she and her mother fled to the Mist Continent by boat when the village was destroyed. Sarah's mother perished before arrival, and the King of Alexandria found Sarah and took her as his own child to replace his recently deceased biological daughter, named Garnet. The Final Fantasy IX Ultimania elaborates that the girl had lost her memories in the calamity, and didn't question it when her new adoptive parents let her know she had always lived in Alexandria Castle.
Sir Fratley was Freya Crescent's lover in Burmecia who left to travel the world and never returned. Freya set out to find her lost love, but when she does, she discovers Fratley is suffering from amnesia and does not remember her. It is implied they become a couple again after Kuja's threat has been removed, although Fratley never regains his memory.
There is a man who actually got Sin's toxin after the destruction of Kilika. He can't remember anything including his own name so he just sits at the port, hoping someone will recognize him.
During the War of Transgression, 600 years ago, Fang and Vanille were tasked to become Ragnarok and lay waste to Cocoon. Fang ended up becoming Ragnarok alone and her incomplete Ragnarok cracked Cocoon's shell, whereupon the two were placed in crystal stasis by Goddess Etro.
600 years later, Fang and Vanille recover from crystal stasis, but Fang has lost all memories of her previous Focus and her time as Ragnarok. Vanille, wanting to protect Fang, hides the truth. Although Fang never truly recovers her lost memories, she can piece together the true events from the suspicious way Vanille is acting.
As a time traveler from 700 years in the future, Noel Kreiss possesses knowledge of the events between Serah Farron's time and his. However, his memory is affected by the paradoxes and corruption of the timeline, and he is unable to recall some basic historical facts that would help direct him and Serah on their journey. The effect gets worse as the timeline keeps changing due to their actions.
Mog, Serah and Noel's companion on their quest, also lost most of his memories when he fell into a paradox in the Ocean of Time. By solving the anomalies in Oerba of 300 AF and 400 AF, Serah and Noel can help Mog remember his past.
Due to her existence as a paradox effect, Alyssa Zaidelle's memory is corrupted, although the events of the true timeline regarding her manifest during her dreams.
Cid nan Garlond suffered amnesia in the aftermath of the Calamity, and was taken in by Father Iliud of the Church of Saint Adama Landama. As "Marques", he worked as a priest until Alphinaud sought him and the adventurer out to revive the Scions. Cid slowly recovers his memories as they scour Coerthas for his missing airship, the Enterprise, and only once it is fully repaired and he is piloting it, does he fully recall his past.
- Nine: "Even though I heard the numbers, I just don't get it."
- Seven: "It's all buried in our memories. There's death all around us, but it doesn't sink in."
- —Nine and Seven discussing their lack of memory of fallen comrades
As an effect of the Crystals, most individuals have their memories of those that they know erased upon that individual's death. Despite this, associated feelings will sometimes manifest as déjà vu. Additionally, the existence of such individuals is recorded through Knowing Tags so that they are not entirely forgotten. Those branded as l'Cie are exempt from this effect, but will eventually begin to lose all memories and emotions due to their extended service. Others can still remember sublimated l'Cie, even if they are considered dead.
Some view the memory erasure a blessing from the Crystals that allows people to carry on their lives even after big losses, but others resent and fear it, not wanting to be forgotten and not wanting to forget those once close to them. Some also take comfort in the fact that if they can remember someone then they know that individual is still alive, even if they are separated by a great distance. Others, though, are less comforted, as the individual in question may still be in mortal danger and about to die, or still alive but suffering greatly. People speculate over why they can still remember sublimated l'Cie, some pondering that l'Cie live such extraordinarily long lives that no one who used to know them as human is no longer alive. However, the true reason may be that upon entering crystal stasis, the l'Cie's soul is trapped in crystal in the mortal plane, and thus they are not truly considered dead.
The Crystals were created by Arecia Al-Rashia, a supernatural and immortal being who is in Orience to enact the god Pulse's plan to find and open Etro's gate, the gateway to the unseen realm where human souls pass onto upon death. She wants to cultivate Agito, the perfect soul that would reveal the gate for even those who have not died. She believes the souls would be tempered via warfare, and thus the Crystals remove the memories of the dead from the living so that the wars plaguing Orience would not quell, allowing one Crystal to eventually reign over the others and trigger Tempus Finis. If Tempus Finis comes and there is no Agito, the world is destroyed and reborn, the spiral starting anew with the souls of those died in the war returned to the cycle.
The cadets of Class Zero, Arecia's handpicked souls to become Agito, eventually defeat The Rursan Arbiter as humans after rejecting the Vermilion Bird Crystal's offer to become l'Cie. The Arbiter is the Judge who is to test those who want to become Agito in their worth. After deeming Class Zero worthless, the cadets yet prevail and stall Tempus Finis, but die in the process. Arecia is surprised by the result and listens to the cadets' souls to learn they do not want to be revived for another cycle. Though not human, Arecia has developed a bond to the cadets as their adoptive mother, and heeds their request. She abandons the experiment to find Etro's gate with the Agito and departs from Orience to places unknown. The light of the Crystals fades and people regain the ability to remember the dead.
Ringabel has amnesia, to the extent that he has forgotten his real name and adopted a moniker supposedly given by the townspeople of Caldisla. He carries a mysterious journal and uses the author's written accounts to justify the party's next objective. After defeating Alternis Dim aboard the Grandship, the dark knight's helm breaks to reveal his face is that of Ringabel's. Ringabel takes to comparing the journal Alternis dropped with his own, realizing the written accounts are similar. After defeating Alternis a second time Ringabel starts to recall fragments of his memory, and after awakening three crystals in the third version of Luxendarc, he finally remembers his past as the dark knight, along with hailing from a different Luxendarc than his companions, and that Airy is deceiving the party.
Airy claims to have amnesia every time the party passes through the Holy Pillar only to awaken in a world where the Great Chasm is still present. This is only a ruse to convince the party to reawaken the crystals in each world they appear in, as they still retain their memories when they pass through the light.
Warriors summoned to World B to fight arrive with no memories. As they fight, their memories of their past lives and worlds gradually return, but if they are defeated in battle, Shinryu absorbs their memories of the cycle they were fighting in and revives them in the next cycle.
The warriors retain the memories of their home world, but have no recollection of previous cycles. Those who are not defeated retain their memories into the next cycle, but once defeated, all memories of previous cycles are absorbed.
The Warrior of Light and the other warriors of Cosmos believe he is suffering from a more severe case of amnesia, but it's later explained he has no memories of a life outside the cycles because he was born during the cycles.
After Onion Knight saves Terra from the Cloud of Darkness, she has no recollection of her forced battle against the Onion Knight due to her powers going out of control, something Onion Knight attempts to hide from her for her protection. As soon as she learns from Kefka Palazzo about the event, Terra becomes disturbed and nearly relapses until Cloud Strife puts her back to her senses at her request.
Upon awakening in Nine Wood Hills, Reynn and Lann have no memory of their past as Mirage Keepers in which they gathered various Mirages and gained enough power to rule the entire world if they so chose. They have also lost almost all memory of their family and set out on a journey to find their mother.
- The incarnation of amnesia related instances in school centered settings in Final Fantasy is likely a parallel to the occurrence of the coming of maturity and adulthood in relation to one's memories over their lifetime, as it is believed that as one ages and engages in the responsibilities of adulthood, memories of nostalgic and cherished importance are phased out and are harder to remember.
- When Krile rendezvouses with her grandfather in Final Fantasy V, Galuf at first acts like he doesn't recognize her with a question mark appearing over his head. He then remembers her and tosses the question mark off the side of the screen.
- ↑ Quote:KEYWORD War of Transgression - The war broke out approximately 600 years ago (666 years ago according to one theory). (KEYWORD 黙示戦争 - 約600年前に（一説では666年前）に勃発した。) Final Fantasy XIII Scenario Ultimania. pp055.