>>718792023
That's basically how the solo game Thousand Year Old Vampire goes. After dozens of prompts you'll forget everything about your human past, how you turned into a vampire, even events that happened after that. The only thing that can hold these old memories is a diary that will inevitable be destroyed, and with it what remained of your past. I think something similar would also happened outside the game, you would no longer be you after some time, at least to everyone but some otherworldly observer, if that makes sense.