A traveling man walks into a bar, puts down his heavy suitcases, and starts playing with his watch. A rather sad, lone drinker starts asking questions. The watch man is quite happy to show it off.
"What does it do?" asks the drinker. "Everything!" is the answer. "Look."
The watch man presses buttons. Beeps are emitted. The watch makes a phone call! The watch shows the time in several countries, simultaneously. Next, the watch man twiddles a dial and, after some squeaking, a moving picture swims into view -- television.
The drinking man is impressed. Amazed in fact, and asks the watch man how much he wants for the watch. The watch man smiles, and presses another button. Music plays, the clearest, loudest music the drinking man has ever heard. Then the watch man explains that the watch will make coffee, type up reports and attract all women.
"I love this watch," says the watch man, "but I will sell it to you for just $50."
This is, of course, a bargain. The drinking man hands him the money. The watch man hands him the watch and walks away.
"Wait!" says the drinking man, "You forgot your suitcases."
"Those," says the watch man, "are the batteries."