Are surgeons and doctors glorified mechanics?

This question reminds me of an old joke:

A famous surgeon takes his car to a mechanic. The surgeon and the mechanic strike up a conversation while mechanic is working on his car. He says to the surgeon, “You and I, we kinda do the same thing, eh? We look for the part that isn't working, then fix it or replace it. But you get the big bucks!”

The surgeon coughed into his hand, then gently replied, “Now, can you do it with the engine running?”

- Jill E. Griffin, on Quora.