A man was seated next to a little girl on an airplane when the man turned to her and said,
'Let's talk. I've heard that flights go quicker if you strike up a conversation with a fellow passenger.'
The little girl, who had just opened her book, closed it slowly and said to the man, 'What would you like to talk about?'

'Oh, I don't know,' said the man. 'How about nuclear power?' and he smiles.

'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 the same stuff - grass. 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 man, visibly surprised by the little girl's intelligence, 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?'