Establishing an Unreachable Baseline
"Chords, vibrations, and harmonic ecstasies echoed passionately on every hand, while on my ravished sight burst the stupendous spectacle of ultimate beauty."—"Beyond the Wall of Sleep" by H.P. Lovecraft
An experience is so extreme that it makes all subsequent (and less importantly, prior) similar (yet far less extreme) experiences seem bland and a pale imitation of the perfection that the victim has tasted (be it literal taste or figurative).
Maybe someone heard a joke, and it's so funny that nothing else can make that person laugh. Or someone went into the Land of Faerie and in typical tourist fashion, decided to try out the local cuisine and now because his standards are so high, everything else he tastes would be like a normal person tasting sawdust -- and there is a good chance he considers regular food so unpalatable he will probably choose to simply starve if denied access to fairy food.
Regardless of what the experience is, though, it has spoiled the subject for anything lesser. And if denied any more chances to experience the lofty heights he once attained, the victim may well find life not worth living -- or at best a drab and grey place with little to recommend it.
Note that although the text above (mostly) frames the trope in terms of pleasant experiences, this isn't exclusively the case. A person who has felt the ultimate in pain may end up something along the lines of Too Kinky to Torture simply because lesser torments simply can't compare.
See also Tough Act to Follow. Compare Sense Loss Sadness, Orgasmically Delicious. By contrast Brain Bleach causes unending non-physical discomfort, even after the event that caused the experience has passed. Compare/contrast Go Mad from the Revelation which typically leaves an psychological impact beyond the assessed potency of sensations.
- Sometimes shows up in Harry Potter fanfic, when (sane) survivors of the Cruciatus curse are no longer particularly bothered by lesser painful experiences.
- In Warhammer 40,000, followers of Slaanesh do something like this to themselves, causing them to seek out ever increasingly intense sensations.
- A researcher at the SCP Foundation did this by requesting the perfect drink from SCP-294. He then committed suicide. "I'm sorry, but at this point everything's just one big letdown."
- Kirito and Asuna do this in Sword Art Online Abridged when they have a taste of a stew made with an S-class ingredient. Kirito even notes that Asuna Algernoned their taste buds.
- In South Park, Cartman can't laugh after seeing people with faces that look like butts.
- In the Rick and Morty episode "Morty's Mind Blowers", irked by Morty's insistance on using a level (a crude instrument by intergalactic standards), Rick builds a machine that creates a surface with "true level". After stepping on it, Morty (sarcastic at first) experiences orgasmic pleasure from standing. And then Summer takes him back to a normal floor...
Morty: Everything is crooked! Reality is poison! I wanna go back! I hate this!
- This prompts Rick to remove that memory from Morty's mind.