A truck driver hauling a tractor-trailer load of computers stops in a bar for a beer. As he approaches the bar he sees a big sign on the door saying "NERDS NOT ALLOWED-ENTER AT YOUR OWN RISK!"

He goes in and sits down. The bartender comes over to him, sniffs, and says, "You smell kind of nerdy, and just what do you do for a living?"

The truck driver says, "I drive a truck, and the smell is just from the computers I'm hauling."

The bartender says, "OK, truck drivers are clearly not nerds," and serves him a beer.