Okay, like hypothetically, let's say you sold your memory of your tenth birthday to the devil because your hamster died and he could bring it back for the price of something that meant a lot to you. So you sold it.
And then you get dumped somewhere else like, oh, another world that's 150 years in the future. And you start remembering that party again because the magic or whatever got strained or broke. So it's sorta like the deal went bust because you got the memory back.
So the devil doesn't really have it, right? Everything's okay?