A mechanic was removing a cylinder from the engine of a 172, when he spotted a world-famous heart surgeon in his FBO. The heart surgeon was waiting for the service manager to come take a look at his aircraft. The mechanic shouted across the garage, "Hey Doc can I ask you a question?" The famous surgeon, a bit surprised, walked over to the mechanic working on the 172. The mechanic straightened up, wiped his hands on a rag and asked, "So Doc, look at this engine. I also can open hearts, take valves out, fix'em, put in new parts and when I finish this will work just like a new one. So how come I get a pittance and you get the really big money, when you and I are doing basically the same work?" The surgeon paused, smiled and leaned over, and whispered to the mechanic: "Try doing it withthe engine running!"
The reason mechanics don't make good surgeons, or near the same amount of money is we tend to omit that you got to do it with the engine running.