All electrons in Universe are identical, it’s absolutely impossible to discern two electrons one from another. It’s called the Indistinguishability Problem.
Other particles, like protons, neutrinos and positrons show the same peculiarity.
That leaded John Archibald Wheeler to a crazy idea: what if every electron was all the same one? The “one electron” must exist through all the existence and back again, over and over. Maybe taking the long way home as positon, maybe sometimes through a shortcut in a dead dimension we barely understand.
That hypothesis possibly solves a lot of Quantum Physics questions – if not all of them, including the huge amounts of matter and antimatter during the first ages.
But I’m more interested in the metaphysical implications. Consider this: every indistinguishable particle in our body may be the same one, in diferent moments of its own existence, separated by an unintelligible amount of time, through all ages, up to the end of time, and back to the very beginning… uncountable times.
Let’s get philosophical now.
What if we can extrapolate even the most abstract concepts? The self-sense (consciousness if you rather), understood not as a computational result of interactions between neurons, but otherwise it might be a kinda particle itself, traveling through space and time from the numinous singularity to the cold dark end and back, and back again.
Thinking that big, every being ever was, is, or’s to come is the very same being. You’re me (and we are that crawling cockroach you just saw.)