My young son noticed a leaky valve leading into our hot water tank. I called my plumber who came over to repair the valve. I paid him $100 for the service call. When I told my son, he was shocked. "But it only took him 5 minutes!" I told him that was the whole point. If I had done the repair, I would have taken the day off work, my son would have learned some choice new vocabulary, we'd be up to our knees in water.

And the pipe would still be leaking.