It's been a bit odd for me working at the school. In college, we all called the professors by their first names, so it's not like it'd be odd for me to call a teacher by their first name. But being thrust into the elementary/middle school environment again, I find it nearly impossible to get myself to call any of the teachers there by their first name, even when referring to them to other people. We're all adults here and some of them look like they're younger than I am. Strange what the mind can do.
Of course, it's entirely possible that I have a teacher fetish of some kind and I want them to teach me a lesson, but that doesn't seem too likely.