[furyofantares]

I had a professor who had taken courses from Paul Halmos, who authored one of my favorite math books, Naive Set Theory. I regarded the book so highly that I was somewhat star struck to learn my professor had taken courses from him.

I asked my professor what it was like, was he an incredible professor? He told me the lectures were useless! I was shocked and he said they were so well prepared they were effectively a recording of the material - and no advantage over reading the book. At that point I reflected and realized that, by far, my favorite professor was one who constantly made mistakes while solving problems on the board. He'd have to notice something wrong and track down the error, and it was wonderful and highly instructional to watch the process.