Somebody has harmed . If you take revenge , do harm in return , both you, and the one who has hurt you. That could lead to the other’s desire for revenge and to make your new worst. It follows a real chain reaction , a vicious circle of ill will which can not go out only when you change your perspective and you will prove the maturity needed to break it , giving up mischief . Desire for revenge , besides strong negative feelings that is needed to support it, requiring a considerable amount of energy. Whether it’s a spontaneous revenge or elaborate one , it takes effort and it takes your mind off other things. It is more constructive to use all this energy doing something practical , something to make you better yourself and not your ego , and that only temporarily .