A few weeks after the Graybeard engineer retires, the big machine breaks down. Manager tries everything he can think of, but cannot get the machine working again. He calls in Graybeard.
Graybeard walks into the factory, climbs onto the big machine and inspects it carefully, talking to it as a man talks to a horse. He stops, calls for a sledgehammer, then whacks the machine once, whereupon it starts right up. Graybeard leaves and the factory is humming once again.
The next day, Manager receives a bill from Graybeard for $5,000. Manager is furious at the price and refuses to pay. Graybeard assures him it is a fair price. Manager retorts that if it’s fair, Graybeard wouldn’t mind itemizing the bill. Graybeard agrees and sends the new itemized bill:
Hitting the machine with the hammer: $5
Knowing where to hit: $4,995