Naming beyond the names

When I was on study abroad in Berlin, our professor came to have dinner with the family that was putting up with–I mean, putting up six students from our university. This professor was an 80-year-old German who was kind of a grandfatherly figure among the students: gruff, soft-hearted, funny, exasperating, totally uninterested in political correctness, and dear to our hearts in spite of the times he drove up absolutely up the wall.

We, being young American students, generally addressed him as...