This is an experimental thread. It is somewhat in the spirit of the Rationality Quotes Thread but without the requirements and with a focus on humorous value. You may post insightful jokes, nerd or math jokes or try out rationality jokes of your own invention.
ADDED: Apparently there has been an earlier Jokes Thread which was failry successful. Consider this another instance.
"I'll have a beer", the first one says. "I'll have two beers", says the second. "Three beers, please", says the third.
The bartender says, "you guys owe me a twelfth of a beer."
I don't get this one.