This is a type of afterlife where people only exist as long as they're remembered. What happens when someone fades varies but it most commonly means the Cessation of Existence.
Sister trope to Clap Your Hands If You Believe, where things or beings stop existing when there's no one left who believes in them. Compare to God Needs Prayer Badly where a deity only exists as long as they have followers.
- Bleach anime episode #3. After her brother Sora dies, Orihime Inoue regularly prays for him, which gives him peace in the afterlife. After a year she starts to pray for him less and less and begins to forget about him. After she enters high school, she stops praying for him altogether. His sadness and loneliness cause him to not pass on to the Soul Society, which leaves him vulnerable to being converted into a Hollow.
- In One Piece, shortly before his Heroic Sacrifice, Hiruluk gives a speech declaring that a man doesn't truly die until he is forgotten.
- In The Book of Life, people go to the permanent party that is the Land of the Remembered after they die. Once they're forgotten, they're transferred to the much gloomier Land of the Forgotten.
- In Coco the dead are only allowed to visit the land of the living on the Day of the Dead if someone has left their photo in an ofrenda, family shrine. And if they are completely forgotten by the living, they die the Final Death and fade away. It's unknown what happens afterwards but it's implied they cease to exist.
- In Titan A.E., the Hodrians believe that as long as a person's name is still out there, they endure. So they create "memory spheres", basically glass capsules with the name written on a slip of paper inside. Much of their activity consists of finding new places to stash the things; their original planet is buried in them.
- The Cowtail Switch features this trope as an Aesop. The setting is Africa. A father goes out hunting and never comes home. His wife, (Who was pregnant at the time) gives birth to yet another son. When he grew old enough to speak he asked "Where is my father?". This prompts the older boys to search for him. They find his bones and one of them opts to put them back together. Another found his flesh and sinews. The third breathes life back into him. Overjoyed, they all return home and the father says he will reward the son who had the biggest hand in bringing him back to life with a Cowtail Switch. The older boys quarrel among themselves only to stop when their father gives the switch to his youngest son. They knew that his judgement was correct because a man is only truly dead when he is forgotten.
- A variant in the Divine Comedy, many of the damned in Hell ask Dante to tell their stories when he goes back to the world of the living so they can be prayed for.
- In Warrior Cats, cats that live in Clans (feral colonies) join StarClan after they die if they lived a honorable life. If they didn't follow the warrior code, then they end up in the Dark Forest. Spirits stay in StarClan until they become completely forgotten by all other cats (dead or alive). Once they're forgotten, they fade. What happens when they fade is uncertain. They either turn into stars and live peacefully by themselves from thereon, become part of a second StarClan, or they stop existing period.
- In the 2002 Russian novel Light in the Window by Svyatoslav Loginov, everything in the Afterlife revolves around memories of the living. For each time a living person remembers the dead one, they receive a coin: golden one the living knew them personally, silver one otherwise. Coins can be used up to fulfill any kind of wishes, with a complex Rule Magic system based around wish fulfillment. If you run out of coins, you disappear forever.
- In the Chronicles of the Kencyrath, this is particularly a plot point in Bound in Blood.
- Ciaphas Cain (HERO OF THE IMPERIUM) often claims he's a complete Dirty Coward who'll happily throw all the men under his command between him and danger so he can run away. He also expresses guilt that he can't remember the face of a man who died under his command. Yeah.
- A recurring line in Going Postal is 'A man's not dead while his name is still spoken'.
- The second volume of Spirit Hunters (based loosely on Japanese mythology) has a ghost who is barely more than an indistinct cloud due to his name being stricken from all records. The Hunters are compelled to find some trace of the name so he can be properly put to rest.
- In Seeker Bears, grizzly bears believe that souls flow in the river after death. They flow into the sea once they're forgotten.
- Westworld: Alluded to by one of the hosts in Season 2:
Akecheta: You live only as long as the last person who remembers you.
- Exalted has one of the lighter examples, surprisingly. When mortals die their soul is drawn to the Lethe where their memories are erased prior to Reincarnation, but they can resist the Lethe's pull with Essence that can be imparted by worship (like any other supernatural being in Creation) or stolen vampirically.
- Warhammer 40,000 on the fortress world of Cadia the mortality rate is so high that if the name on one's tombstone becomes illegible from wear they dig up the remains and inhume a fresh corpse in the grave. Figuring that it's not worth wasting a gravesite on the forgotten.
- In Liliom, this is told to the title character after he dies:
"Your name is still spoken. Your face is still remembered. And what you said, and what you did, and what you failed to do—these are still remembered. Remembered, too, are the manner of your glance, the ring of your voice, the clasp of your hand and how your step sounded—as long as one is left who remembers you, so long is the matter unended. Before the end there is much to be undone. Until you are quite forgotten, my son, you will not be finished with the earth—even though you are dead."
- Alluded to in one of the loading screen quotes in Might and Magic: Heroes VI
"A thing lives only as long as the last thing that remembers it".
- Final Fantasy X. There's a special location called the Farplane where the local spirits can bring back an image of the dead, people usually do this to clear out any bad feelings "face-to-face".