Uncle Dave, your "Oldest Profession" joke reminds me of a similar one:

Three engineers were wondering what kind of engineer God must be. The electrical engineer claims it has to be his profession. "Look at the nervous system, and incredible matrix of impulses allowing control of every part of the body."

"No," says the mechanical engineer. "Look at the blood system. It carries nutrition and hormones to each part of the body and eliminates waste the same way. It's a perfect system."

"Nope," replied the third person. "He HAS to be a civil engineer."

"What?" cry the other two. "How can you say that?"

"Who else," said the civil engineer calmly, "would run a sewage disposal system through a major recreational area?"