A little three year old boy, Billy, was sitting on the toilet. His mother thought he had been there too long, so she went in to see what he was up to. Billy was sitting on the toilet reading a book. About every 15 seconds or so, he put the book down, gripped the toilet seat with his left hand and hit himself on top of his head with his right hand.

His mother said, "Billy, are you all right? You've been in here for a while."

Billy said, "I’m fine, mommy. I just haven't gone potty yet."

His mother said, "Ok, you can stay here a few more minutes. But Billy, why are you hitting yourself on the head?"

Billy said: "Works for ketchup…''