Some people need small reminders that what they're doing is not only annoying but bad etiquette. For some reason, if you say someone lacks decorum it makes them straighten up their back more than if you accuse them of any kind of systemic impropriety. I guess people don't want to seem undignified. If he asks you a math question, just say, "I'm not in the mood to entertain today" and go off to do a task. There is a certain skill that forms after a number of these inconveniences that I will call "withering unaccountability." There is nothing more terrifying than a woman who can go from sunny to cutting at the drop of a hat—and with nothing to pin on her! Get to know your anger from all angles. A little rage can be enlivening.