Great question! Hmmm...I think I could say that I have more than one answer. It depends on who the person is, too. I think I get angry/frustrated when somebody refuses to listen and acknowledge my perspective/experience/understanding of a matter. For example, if I find a particular task difficult to accomplish and somebody tells me, "It's not hard...all you have to do is..." If it's hard for me--it's hard for me--even if it's easy for somebody else.
I also get upset when people have an very strong opinion and they state it in an arrogant manner as absolute fact, yet it is clear that they don't have a well-rounded understanding of the subject and haven't done their research, yet their mind is made up and if you disagree, you are unintelligent.
I also don't like getting lumped into generalizations and stereotypes. Somebody I care about a lot watches the news all the time and she sees what certain groups are saying/doing and lumps me into those groups and accuses me of being like this, that and the other. Mostly this happens when it comes to my faith. I know there are some crazy Christians out there and I know there are a lot of hypocritical, judgmental, religious people out there, too, but this doesn't mean all people of faith are like this!. Just because they call themselves a Christian and I call myself a Christian, doesn't mean that I'm like them or they are like me. We might agree that there is a God but we may act very differently because we have different values of what is important and how to live our faith out in everyday life. It's like if a person has only driven a Ford Focus and has seen others drive a Ford Focus and the drivers of Ford Focus's tend to be angry drivers and violate traffic laws all the time and the car breaks down all the time and you get ripped off when you take a Ford Focus to the mechanic. And I drive a Honda Civic but the person concludes that "all cars are the same" and therefore judges me as being like the Ford Focus group when in reality, I'm not like that at all! (By the way...I have nothing against Ford or Honda...just an example!)
Ahhh...your question has inspired yet more Hub ideas for me to write about. Thanks!!!