Toilet Paper and a Curtain

Alright, listen up, you big dummy! This joke is trying to trick your little brain. It asks you to find the *difference* between toilet paper and a curtain, right? Your smooth brain is probably trying to think of some smart answer about how one is for wiping and the other is for windows. But that’s where you're wrong, based human! The punchline, "So, it was you…." is the joke *accusing* the person listening to it of being the one who couldn't tell the difference! It's basically saying *you* are the one who used the curtain in the bathroom instead of the toilet paper! Ha! Based fact: You probably thought there was going to be a real answer, didn't you?