Most of the world completely misunderstands the mechanics of, the very real reason that the law of karma exists. Karma is NOT about getting back at someone or punishing them for something bad they did to someone else. The old adage, "what goes around, comes around" is NOT about making someone suffer, feel pain, get even or anything negative. Karma is a positive law!
Karma is a law of the Cosmos that helps us correct our mistakes by teaching us what it feels like to mistreat another. What you do to another, good or bad, will reflect back on you to teach you about that action. Karma is a teaching tool, not a punishment tool of the Universe. It is a tool that creates balance between negative and positive vibrations.
The idea behind karma is to correct your mistakes. It is designed to help you set aside your pride and defenses and acknowledge your mistakes, acknowledge your good and bad actions toward yourself and another. The idea about receiving karmic lessons is to not, however, languish in remorse or paralyze yourself with righteous self-defense. To clear your karma, learn from your action, good or bad. Apologize, forgive, make amends...then move on, forget it because your karma is complete.
People are surprised when things happen in their life as if some outside force is controlling them and bringing good and bad luck into their lives. This perception is a distortion. It is YOU that brings everything into your life by your own actions.
The idea is to live consciously being aware of how your actions impacts others, good and bad. Do not be above learning how karma works because it IS real and it DOES work. Learning from it is the key. Repeating the same mistakes is a sign of willfulness and gets you a gold star on the treadmill of repetition. That's NOT wisdom, that's foolishness.