"The details are kind of fuzzy, since...y'know, I don't remember them myself. What basically happened, I think, was that when I was here, I learned about the future of my world, and when I left the Bar, I tried to change it, and it really screwed things up and made this alternate universe. I...can't quite remember how getting my memory erased fixed that, but it ended up all right, so I guess it was worth it."

He can be perfectly cheerful about this a year or two after the fact.