I’m a fairly thoughtful person by nature. If asked to list my hobbies or favorite pursuits, I always put thinking at the top of the list. Once upon a time during a free period, I was seated at my desk thinking. A student walked in and asked if I could help him out with a knotty math problem since it didn’t look like I was busy with anything just then. I’m pretty good-natured, too, so I just smiled and said that I’d been busy thinking, but that I’d be glad to help out anyway. After we’d worked our way through the problem, I hoped he’d learned two things, viz., how to think a little bit more effectively math-wise and that despite appearances, thinking is indeed something that someone might be busy with.