I like David Sedaris, Christopher Moore, and Chuck Thompson when it comes to laugh-out-loud funny books. A friend of mine pointed me to Christopher Buckley, who is featured in this month's Commonwealth Club magazine (p. 39):
You may know of the situation of the teenage boy who has to do a report for school on the difference between hypothetical and reality, so he goes to his father one night and asks him if he could give him a hand with it. The father thinks for a bit and he says, "Go ask your mother if she would sleep with a total stranger for a million dollars." So the son goes off and he comes back pretty quickly [and says] the answer is, You bet. So the dad says, "Go ask your sister," and the boy comes back quite lickety-split, and reports the answer as, "Totally." The dad says, "There you go. Hypothetically, we're sitting on two million bucks. In reality? We're living with a couple of hookers."
I think he's modifying something Churchill said, but it's still funny.