The mechanic

A motorcycle mechanic is working on a Harley Davidson. He is removing one cylinder head when he notices that a famous heart-surgeon has walked into the shop. Being a cheeky type, he stands up, wipes his hands and calls the surgeon over.

"Doctor", he says, "do you mind if I ask you a question?".

"Sure" says the surgeon.

"Well, here I am working on this engine", says the mechanic. "I will open it up, replace the valves and reassemble it. When I've finished, it will run as good as new. The funny thing is that you, a surgeon, and me, a mechanic, are basically doing the same job… why is it that you get paid the big dollars and I don't?"

The surgeon thinks for a moment and then smiles. "You, try doing that while the engine is running!", he replies.