The Proctological Mechanic
A gastroenterologist had been in practice for 20 years and had settled into a very comfortable life with his future being very secure. So he decided to fulfill his REAL life's dream and become an auto-mechanic.
Having entered mechanic school, the former physician received the results of his first test back with a score of 200%. Confused, he asked the teacher why such a high score...
"Well", said the teacher, "The first part was taking the engine apart and you did that perfectly so you got 50%. The second was to put it back together again and you did it perfectly and got another 50%. The other 100% was for doing it through the tailpipe."