The Unhappiness of the Mind

It creates an enormous amount of unhappiness because it has things to say about you that you are not good enough. I can think for hours about yesterday when somebody was offendid me and after it happened, i start thinking, i should have said that. How dare he not respect me? Just people like that shouldn't be allowed to exist. This is just, you can go on for hours thinking about and you feel more and more angry. But the mind, even there, can get in there and amplify that instead of saying, ok, it's finished, gone. Just be present.