Guy gets on a plane and finds himself seated next to an attractive brunette. He immediately turns to her and makes his move; "I've heard that flights pass quicker if you strike up a conversation with your fellow passenger, so let's talk"

The brunette who had just opened her book, closes it and says; "What would you like to discuss?"

"Oh I don't know," says the guy "how about nuclear power?"

"Well that could be interesting, but first let me ask you a question. Horses, cows and deer all eat grass. Yet the deer excretes small pellets, the horse muffin sized chunks and the cow big squishy pancakes. How come?"

Dumbfounded the man replies; "I have absolutely no idea"

"I see" says the brunette, "So you feel qualified to talk about nuclear power, but clearly you don't know shit!!"