Two strangers were seated next to each other on the plane when the first
guy turned to the second and said, "Let's talk. I've heard that flights
will go quicker if you strike up a conversation with your fellow
passenger."

The second guy, who had just opened his book, closed it slowly, took
off his glasses and said to the first guy, "What would you like to
discuss?"

"Oh, I don't know," said the first guy. "How about nuclear power?"

"OK," said the second guy. "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 first guy. "I have no idea."

"Well, then," said the second guy, "How is it that you feel qualified
to discuss nuclear power when you don't know ****?"