Exciting news: The worlds oldest joke has been documented! The joke dates back to 1900 BC, and is credited to the Sumerians. Here is the joke:
"Something which has never occurred since time immemorial; a young woman did not fart in her husband's lap."
Huh. Well, I guess if nothing else this proves that fart jokes have been funny for a lot longer than I would have thought.
I would like to write more, but I hurt my back the other day and simply don't feel like sitting here. Sorry.