What are the most memorable backhanded comments you have received?

From someone I used to hang out with on IRC. (Yes, I am that old.)

“Nick Nicholas! You wouldn’t be half as obnoxious as you are if you weren’t called that!”

Um… I thank you, and my three cousins called Nick Nicholas also thank you?

High school frenemy (well, friend in high school, because I didn’t know any better back then) is in my office a decade later, visiting. I’ve just concluded a call with the French embassy, trying to recover a computer for a staff member in the department, while my frenemy waited.

“Well. That was surprisingly professional.”

Um, say that in my office, will you. Yeah, sod off.