Do Courtesy Titles Matter?

I like to think I’m not fussy about honorifics. I don’t tell my undergraduate students how to address me. The current convention seems to be Professor X, though friends who teach at research universities report that they are often addressed as Dr. X, and frequently undergraduates used to boarding schools will default to Ms. or Mr. X. One colleague, whose last name is difficult to pronounce, goes by Dr. Dan, which students seem to love. Once students have graduated, I usually encourage them to s...