A mechanic was removing a cylinder head from a car engine when he spotted a well-known cardiac surgeon waiting in the workshop. The mechanic shouted out "Hey Doc, want to take a look at this?" The cardiac surgeon walked over to where the mechanic was working.
The mechanic asked, "So Doc, look at this engine. I opened its heart, took the valves out, repaired or replaced anything damaged, and then put everything back in, and when I finished, it worked just like new. So how is it that I make $80,000 a year and you make $800,000 when you and I are doing basically the same work.
The surgeon paused, leaned over and whispered to the mechanic: "Try doing it with the engine running.”