A stranger was seated next to a little girl on an airplane. The plane was just climbing out on takeoff 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 little girl, 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 little girl replies, 'Do you really feel qualified to discuss nuclear power when you don't know shit? "