Little Johnny's father asks him if he knows about the birds and the bees.
"I don't want to know!" Little Johnny says, bursting into tears.
Confused, his father asks what's wrong.
"Oh, Dad," Little Johnny sobs, "first, there was no Santa Claus, then no Easter Bunny, and finally, no Tooth Fairy. If you're about to tell me that grownups don't really have sex, I've got nothing left to believe in."