That's part of what I was worried about - I wasn't sure if it was really my world, or another that happened to be identical. I did my best to make sure the members of the community from that world never worked out who I was; it wasn't hard, since I looked a lot different at the time.

I know there are people who have prevented incidents that would have ended in another member's death, but as far as I know they've never done that to their own world. Partly because the timeline discrepancy happens so seldom, I think.