today's email joke, an oldie but goodie

given my profession, i've liked this joke since first hearing it. a loooooong time ago.

A stranger was seated next to a woman on the airplane when
the stranger turned to her and said, "Let's talk. I've heard that
flights go quicker if you strike up a conversation with your fellow
passenger. " The woman, who had just opened her book, closed it
slowly and said to the stranger, "What would you like to talk
about?" "Oh, I don't know", said the stranger. "How about nuclear
power?" "OK". she said. "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?"

The stranger thinks about it and says, "Hmmm, I have no idea." to
which the woman replies,

"Do you really feel qualified to discuss nuclear power when you
don't know shit?"