A stranger was seated next to Little Johnny on the plane when the stranger turned to the Little Johnny and said,
- "Let's talk. I've heard that flights will go quicker if you strike up a conversation with your fellow passenger."
Little Johnny, who had just opened his book, closed it slowly, and said to the stranger,
- "What would you like to discuss?"
- "Oh, I don't know," said the stranger. "How about nuclear power?"
- "OK," said Little Johnny, "that could be an interesting topic. But let me ask you a question first. A horse, a cow, and a deer all eat grass. The same stuff. Yet a deer excretes little pellets, while a cow turns out a flat patty, and a horse produces clumps of dried grass. Why do you suppose that is?"
- "Jeez," said the stranger, "I have no idea."
- "Well, then," said Little Johnny, "how is it that you feel qualified to discuss nuclear power when you don't know s#it?"