Just can't break old habits

Sometimes I hear a joke I just have to pass on and remember here it goes...

A gynecologist had become so fed up with malpractice insurance and HMO paperwork and was burned out. Hoping to try another career where skillful hands would be beneficial, he decided to become a mechanic. He went to the local technical college, signed up for classes, attended diligently and learned all he could When the time for the practical exam approaced, the gynecologist prepared carefully for weeks and completed the exam with tremendous skill.
When the results came back, he was surprised to find that he had obtained a score of 150%.
Fearing an error, he called the instructor, saying, "I don't want to appear undgrateful for such an outstanding result, but I wonder if there is an error in the grade."
The instructor said, "during the exam, you took the engine apart perfectly, which was worth 50% of the total mark. You put the engine back together again perfectly, which is also worth 50% of the mark. This equaled an A. After a pause, the instructor addded, "I gave you an extra 50% because you did it all through the muffler, which I've never seen done in my entire career!"