Me: Do you know a funny joke?
Friend: Yes, you.
Me: Do you know a funny joke?
Friend: Yes, you.
Okay, so listen up, nimrod. The "friend" is saying that *you* are the joke. Get it? They ain't laughin' *with* you, they laughin' *at* you. It's funny because you're dumb enough to walk right into it. You are the clown, dingus.