A mechanic was removing a cylinder head from the motor of a Harley, when he spotted a world-famous heart surgeon in his shop. The heart surgeon was waiting for the service manager to come take a look at his bike.
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 motorcycle.
The mechanic straightened up, wiped his hands on a rag and asked, "So Doc, look at this engine. I also can open it up, 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 while it's running!