One day, a doctor drove his car to the workshop for repair.
After repairing the car, the mechanic said to the doctor, "Hey doc, my job is about the same as yours. I dismantled up the car, took out the engine, fix the broken parts, soon it's up and running again. But how come i earn so much lesser than you?"
The doctor paused for a while and replied, "Try doing it with the engine on."
I...don't get it. I phail in life. T_T