An auto mechanic in the hospital was chatting nervously with his surgeon while being prepped for an operation. "Sometimes I wish I'd gone into your line of work," he told the doctor. "Everything you doctors do is so cut and dried and tidy. With me, I spend half a day taking an engine apart and putting it back together, and it seems like I always have a couple of parts left over." "Yes," said the surgeon. "I know the feeling."