Here’s a freaky thought:
Think about that shit.
It’s got its own DNA. It’s like a completely separate bunch of organisms living inside all your cells.
Way back in the pre-cambrian, some single-celled ancestor of ours swallowed some other single-celled thing, and was like, “I’m keeping it as a pet!”
And now we have this little bacteria-type thingie living inside each of our cells.