Once, when I had Harry Lewis as a professor, I was telling a friend something about him, referring to him as "Professor Lewis." My friend asked me if I meant a

Once, when I had Harry Lewis as a professor, I was telling a friend something about him, referring to him as "Professor Lewis." My friend asked me if I meant a different Lewis, as there was more than one professor with that last name, so, to clarify, since he was a professor of computer science, I said, "I mean the CS Lewis." I have called him "C.S. Lewis" to myself ever since.