A heart surgeon came to a mechanic to repair his car. The mechanic had a look at the car's engine, opened a valve and fixed it.
The mechanic said, "I repaired the engine which is the heart of the car. You also operate on the hearts of humans, so our jobs are quite similar. So why it you earn more than me?"
The doctor replied, "Can you repair the car when the ignition is on? We can!"
MORE WAYS TO LAUGH