A man walks into a bar and starts ranting about meta-humor.
"Do you even know what meta-humor is?" he says to the barkeep.
"Um, do I?" says the bartender.
"It's when a joke is aware of its own existence! It's a joke that knows it's a joke, and is aware of its own humor! Get it?"
The bartender is silent.
"What's wrong with you?" says the man. "Why aren't you laughing?"