Hitting the nail on the head

There is an old story about a multi-million dollar power plant that had mysteriously ground to a halt. All efforts to restart it had failed and an expert was brought in. After studying the problem for a few minutes he took a hammer and hit one of the valves. With a rumble, the plant came back to life. Incredulous glances were shared, grateful cries and high-fives were exchanged. Later, the expert’s bill arrived for the amount of $10,000.00. The outraged executive in charge thought “All he did was hit a valve with a hammer, this bill is ridiculous.” he asked for an itemized breakdown and the consultant responded with a bill that read: “Hitting valve with hammer $10.00. Knowing which valve to hit: $9,990.00.”