Well, I think you can choose them, Mrzzy...but most people don't realize that and they have never even considered it once in their lives...thus they are 100% at the mercy of their automatic emotional responses to various triggers.

The only thing that inhibits them in acting out their reactions on the outside is their fear of what may happen if they do...that is, they may feel like murdering their friend or lover or screaming obscenities at a traffic cop, but they realize that the outer act has repercussions they wouldn't want to deal with! So they restrain the outer act, but they suffer fully the turmoil of inner emotions regardless, and that is very hard on their system. Holding in these negative emotions eventually damages the health in various ways, and it leads to all kinds of troublesome behaviour...while bursting out with the negative emotions (venting) can damage other people's health and state of mind. Either way is not helpful.

I've known people who are addicted to anger. To hatred. To feelings of vengeance. To feelings of betrayal. To accusation. To arguing. To grudges. Etc. I've been addicted to things like that from time to time...but not all the time, I hope.

Yes, they do it because on some level they enjoy it...and they feel justified, and they enjoy feeling justified. On another level, though, it causes them (and others) pain. It's not productive, it's a form of emotional illness and dysfunction.

I think it is a choice, but if the one doing the choosing doesn't realize that he is choosing, then he won't be conscious of it being a choice at all. He will feel that it's "just happening", and that he is, in effect, the victim of an external agent of some kind. That's what people normally do.

I think it is no exaggeration to say that most people's lives are unhappy most of the time, due to their own thinking. They experience chronic dissatisfaction, chronic frustration. They live lives of, as one writer put it, "quiet desperation".