Most of us have heard one variation or another of this story. It’s the story where an old engineer/mechanic is called to work on a machine that had been down for some time and critical to get running. The experienced and knowledgeable mechanic inspects the machine briefly, pulls out a hammer, taps on the machine, and the machine begins running. When he invoices the company for his services, the company becomes upset because of the high cost of the invoice. The mechanic itemizes the invoice as usually one to five dollars, depending on the version of the hammer, and the rest of the invoice, usually in the thousands, for knowing where to tap with the hammer.