Warning: the following theories are completely made up and have been disproven by science. Probably.
Imagine a multiverse, where every possibility exists in a separate reality. You could live in a world where cats are the dominant species, or one where pineapple pizza is a staple of every meal.
What if you went back in time and killed your own grandfather before he had kids? Would that make you... not exist? Or would you just become your own grandfather's grandfather?
Ever get stuck in a time loop, reliving the same day over and over? Maybe you're just stuck in a never-ending loop of déjà vu.
That's all for now. Don't get stuck in a time loop on the way out.