The only bit of logic-based public bathroom humor I know is: the difference between men and women is that between the statement [P and not Q] and the statement [Q and not P].
John Allen PaulosThe once-surprising existence of non-Euclidean models of Euclid's first four axioms can be seen as a sort of mathematical joke.
John Allen PaulosWe ourselves are co-called non-linear dynamical systems... I don't feel quite so pathetic when I interrupt a project to check on some obscure web site or newsgroup or derive an iota of cheer by getting rid of pocketful of change.
John Allen Paulos