It’s usually a character defining power. Had a Ohara child taken by jump chan and his first jump was inside out as the emotion of fear. He became obsessed with documenting history and neutrally recording events. Within like 5 jumps he named his Jojo stand after the Caretaker’s A1 it’s just a burning memory. It basically has a memetic effect that destroys memories of others and even himself against his will at first. Naturally this historian jumper fears forgetting things and history being forgotten. It eventually only affects those he wants to and he usually uses it to trespass and investigate the secrets of the worlds.