Two strangers are sitting in adjacent seats in an airplane. One
guy says to the other, "Let's talk. I hear that the flight will
go faster if you strike up a conversation with your fellow
passenger."

The other guy, who had just opened a good book, closes it
slowly, takes off his glasses and asks, "What would you like to
discuss?"

The first guy says, "Oh, I don't know; how about Nuclear Power?"

The other guy says, "OK, that could make for some pretty
interesting conversation. But let me ask you a question first: A
horse, a cow, and a deer all eat the same stuff, but the deer
excretes pellets; the cow big patties; and the horse clumps of
dried grass. Why is that?"

The first guy says, "I don't know."

The other guy says, "Oh? Well then, do you really think you're
qualified to discuss Nuclear Power when you don't know sh*t?"