You realize that you can live in reality, or in fantasy. Anger is based entirely on the fantasy that things should be different, that they can be different. Right now, things are as they are right now. Everybody does what they do because that is the best they can do, right now. Change is possible in the present, but change always requires accepting, fully, everything that cannot be changed, which is to say, the past.
Anger is always about what is already past.
When we get angry we step out of the present and encase ourselves in the past. We tie ourselves fast to the wheel of what has been, of what can only grind on, regardless of what we want, or believe should be, or what we do - because everything we do reinforces the wheel. When we step into anger, into the past, we step into fantasy. Our actions become completely mechanical, reactive, and everything we do reinforces what angers us. Anger is totally blind.