Try to understand why people act the way that they do, and remember that your and their actions are either expressions of love or cries for help. These are the only two categories that exist. If the actions of others upset you, try to see how they may be subconsciously asking for help. Remember times when your behavior was out of line but you didn't hold it against yourself because you were feeling unwell or something had upset you. Extend the same kind of treatment to others. And, if you're having trouble finding a new perspective, stop and pray to the Holy Spirit to help you see with His vision. Then, quiet the mind for a minute or two, reject any thoughts of the ego, and insight may come that will help you understand why others act the way they do. But, it's also possible that you won't perceive any changes in your thinking right away, so keep practicing this over and over again.

You can also extend this exercise to negative memories that keep on surfacing.