The thousand injuries of Fortunato I had borne as I best could, but when he ventured upon insult I vowed revenge. You, who so well know the nature of my soul, will not suppose, however, that I gave utterance to a threat. At length I would be avenged; this was a point definitely settled - but the very definitiveness with which it was resolved precluded the idea of risk. I must not only punish but punish with impunity. A wrong is unredressed when retribution overtakes its redresser. It is equally unredressed when the avenger fails to make himself felt as such to him who has done the wrong.

So if you are angry at someone and plot some kind of revenge, reflect upon this passage for it tells you all you need to know about it. However, I know that a lot of you have subpar intelligence quotients, so here, I've broken it down for you to three points in layman's terms:

1. Revenge is a dish best served cold.
2. If you must pay a dear price for it, then it probably isn't worth it.
3. An eye for an eye, no more and no less.