Everyone gets this wrong

[solost]

@Miller

There’s only one Marty in the movie. When Marty changed the past so his parents didn’t get together, it took “time” (somehow) for the change to propagate all the way down the timeline and erase him from existence. When he fixes things, it sets off another change propagating down the timeline. It will, eventually, catch up to Marty, rewriting his memories so that he remembers “always” having the cool family. But there’s never a “second” Marty - there’s just the one that hasn’t been acclimated to the revised timeline yet.

But part of @Just_Asking_Questions’ point, I think, is not just ‘there should be two Martys, where did the other one go?’, but the fact that ‘cool family Marty’ probably never befriended a much older recluse scientist and never traveled to the past. But if no version of Marty ever traveled to the past, ‘cool family Marty’ would not exist. Paradox.

OK, time travel paradoxes are starting to get exhausting. TIme for me to time out from this thread for awhile…

ETA: posted before I saw the split topic. Sorry!