Mine is that at my age (barely made it into Gen Z on the old end) I just found out today that a Bo Weevil is an insect (beetle) and not some kind of mole or similar rodent.
It’s, uh, boll. Boll weevil. So you learned two things!
While we’re on animals, every time I hear the word mongoose I picture some kind of platypus-like creature. Like, a half goose, half weasel or something. And that’s not what it is at all.