I recently finished a compelling book I had mixed feelings about. It was called Recursion, by Blake Crouch. To spare myself the complicated retelling of the whole novel, I'll just say it involved a device, a chair of sorts, that allowed one to travel back to a vivid memory in one's life and restart a new timeline from that point. From there everything can change.
There were a lot of ramifications and problems to that. Like, other people could get haunted by memories from the now lost, original timeline. And, spoiler alerts galore from here on out, it turns out it is not a good idea to do any of this.
Indeed, it is a very, very bad idea.
So in proper, semi-cerebral, real world science fiction thriller fashion, the end of the world is narrowly averted.
The chair is uninvented.
We go forward from here, on this timeline, as is.
I look over at my wife.