He'd always enjoyed tinkering with engines so thought he'd become a mechanic. So he went along to mechanics school and the final test was to strip the engine completely and reassemble it back into perfect working order. Our gynecologist friend did the test and anxiously awaited his results.

The day he received the results, he got quite a surprise -- he got 150%. He quickly phoned the instructor and asked about the high mark.

The instructor said, “No, that's right. First, I gave you 50% for stripping down the engine -- a very thorough job. Next, I gave you 50% for reassembling it -- a fantastic job really. And then I gave you a 50% bonus for doing it all through the tail pipe.”