A mechanic was removing a cylinder head from the motor of a Harley Motorcycle when he spotted a local cardiologist standing in the shop.
The cardiologist was there waiting for the service manager to come take a look at his bike, when the mechanic shouted across the garage, "Hey doc, want to come over and take a look at this?"
The cardiologist, a bit surprised, walked over to the mechanic working on the motorcycle.
The mechanic straightened up, wiped his hands on a rag, and said, "So Doc, look at this engine. I open its heart, take out the valves, repair any damage, and then put them back together. And when I'm finished, it works just like new."
"So," he continued with a smile on his face, "my point is how come I only make $39,000 a year while you make the really big bucks, basically for doing the same kind of work?"
The cardiologist paused, smiled, and leaned over whispering in the mechanic's ear, ''Now try doing it with the engine running."