Apropos of nothing particular, A Theory:
If you do the whole Star Trek thing, leave Earth behind, explore the galaxy, and boldly go where no man has gone before…
…you will STILL end up face to face with someone you knew in high school, and you couldn’t stand each other then, and it isn’t any better now.
This is my theory, and I would point out that it has never yet been disproved. It is neither logically impossible, nor is there any empirical evidence against it. Which is more than you can say for a lot of crackpot theories.