One of the things I always try to keep in mind when I go in for a casual/relief assignment is to not let the little things/gestures of the first person, which may/would normally be the Director I meet at a centre to aggravate/upset my state of mind for the rest of the afternoon.
Perhaps some people get upset, or are sensitive to a number of things. But as I have learnt from watching my dad (yes, even my dad!).
Being the owner and manager of a business, he learnt to ignore irrelevant gestures/comments and just disregards it. Sometimes he just warns us off with a look, or a comment, or just tells his staff off verbally when they start to panic/whinge/etc.
I really think it is a good skill to learn. Just learn to ignore irrelevent comments and just go in and do whatever work that one has been assigned to set out to do.
And seriously, being a teacher, we have to learn that skill. I had observed recently, a dear friend of mine, who works as a language teacher, and gets easily emotionally upset at the little antics of some students when she is teaching... and they're students who are in their late 20s!
Perhaps she may not have had students who have tried her patience much... I've had children who have bitten me and tore my sleeves/skirt/etc (and they aren't autistic, mine you!), starting running around the class in the middle of a lesson, and etc.... she can't beat that...!
Sometimes these gestures/words may have been said out of frustration, say when the manager has had a really bad day, or maybe she is just is like that, or when some students (who at the age of 28) may still try to be cheeky. *Tsk tsk tsk*
But Always Always try to remember to keep it cool, and don't let it get the better of you! You'll feel much more in control, and better at the end of it. ^^