I find that very often people get angry at others for doing something that they knew they were going to do. They believe the other person is going to act differently than they have in the past - in spite of all the facts that stare them down. This not only takes the choice of happiness out of your own hands, but does so in a way that could have been completely prevented.
I don't know about you, but this sounds insane to me.
More times than not, people are exactly who they tell us they are - who they behave as. Literally, they act and talk in a way that is consistent with who they are and how they think. But, unfortunately, we tend to ignore who people are, and only see them as we think they are (or even worse, the way we want them to be).
In fact, we, as humans, DON'T tend to see people the way THEY are - we tend to see them the way WE are. That may sound crazy, but the truth is, our filters (personal biases) are so strong that we only see what we want to see. It is where the term, "love is blind" comes from.
No matter how someone acts, good or bad, their behaviors are explained, justified, or even blamed because of pre-established opinions we have of them or people like them (based on any number of prejudged characteristics we find in them). If you have had great experiences with "Brown-Eyed" people in the past, we tend to give all "Brown-Eyed" people those attributes. If we met someone of a different culture and found them to be lazy or unwilling to work, then we tend to see all people from that culture with that bias.
It's not right - and we know it's not right, but it is how our subconscious mind works. It does it's best to categorize things and people as much as possible to make it easier to remember and organize.
Truth is, this isn't a bad thing, it simply is - a truth of who we are and how we see those around us.
Unfortunately, there is no magic answer to this problem - giving you clairvoyent awareness of objective reality. It is something that you will have to deal with forever. But there is a solution - a path to easing the impact of these biases. The solution simply requires your awareness of it's existence - the awareness of your personal biases (both for and against certain people).
Once you know that people act, talk and behave who they are, every minute of every day, then you can start to listen more objectively - giving them credit for the good things they do and facing the reality of the things that aren't so good.
Ask questions - of both yourself and of others. Try to find objectivity by finding as many opinions as possible. The more subjective opinions you get, the more the average tends to point to objectivity. Learn all you can about people from them, others opinions of them and yes, even your own biases.
And finally, remember this - you can't change who people are and how people act, that is their choice and their choice alone. However, you can change the YOU respond to how they act. This is the only REAL power you ever have. And finally by realizing YOUR power to choose, you minimize the impact others have over you and your life.