Little Johnny on the Plane

[Rusty24]

A stranger was seated next to Little Tommy on the plane when the stranger turned to the boy and said, "Let's talk. I've heard that flights will go quicker if you strike up a conversation with your
fellow passenger."

Little Tommy, 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 Tommy. "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 Tommy, "How is it that you feel qualified
to discuss nuclear power when you don't know shit?"