High Shower Thoughts

^%29%^

In media, when a character goes back in time and somehow stops their parents from meeting, they have to fix it or else they'll disappear, right?

That's kinda contradictory. Because if they never existed, then they wouldn't have been there to stop their parents from meeting. Things would've run just as smooth as it did before they ever existed.

Question is, what actually happens to them when they alter time. Do they have to start life all over again? Go back just before they screwed up? What!?