To each his own...

A mechanic was removing a cylinder head from the motor of a Harley motorcycle, when he spotted a well-known cardiac surgeon in his shop. The mechanic shouted across the garage, "Hey doc, can I ask you a question?"
Ther surgeon was a bit surprised, but walked over to the mechanic. The mechanic staightened up, wiped his hands on a rag, and said, "So Doc, look at this engine. I open its heart, take the valves out, repair any damage, and then put them back in. And when I finish, the engine works just like new.
You and I are basically doing the same work. So how come I get such a small salary, and you get the really big bucks?" The surgeon paused, smiled, leaned over, then gently whispered to the mechanic, "Try doing it with the engine running."