The mechanic is removing the cylinder head from a Harley engine just as he sees a heart specialist walk into the shop.
The heart specialist waits for the mechanic to take a look at his motorcycle and the mechanic calls out, "Hey Doc! Take a look at this."
The cardiologist is a bit surprised, but walks over to the mechanic. The mechanic sits up, wipes his hands and says, "Hi Doc, look here, I open up the heart of this machine, take the valves out, repair the damage, put everything back together and when I'm finished it runs like new."
"How is it that I earn $39,675 in a year and you earn at least $700,000 although we do exactly the same work?
The cardiologist chuckles and says, "Let's see you to do it with the engine running."