Those of us from my home version of Earth are essentially two people. We are, as far as we can tell, the reincarnations of someone else, so we have two sets of memories. Part of me grew up in Iowa and worked a decade in New Jersey, and another part of me grew up in ancient Wales, was bitten by a werewolf to save my life, and then grew to be second in command of a large pack in London three hundred years later. So the complication is, our first selves can forget our reincarnated selves. That appears to be what happened when I came here.