Deja-poo

Alright, listen up, you cotton-headed ninny muggins! This joke is all about wordplay. "Deja-poo" sounds like "déjà vu," which means you feel like you've experienced something before. But instead of a regular experience, it's about dealing with... well, crap. Get it? It's funny 'cause it's a poopy situation you think you've been in before. You probably deal with this a lot since you didn't get the joke.