"Before you embark on a journey of revenge, you should first dig two graves."

Contrary to self-defense, there is no justice in revenge. And in reality, it ain't gonna be just two graves. Prolonged personal vendetta gives its holders one thing and one thing only: It turns their lives into a living hell. Yes, their lives, not those of others, usually. That's the part that most people fail to see, including the wisdom expressed by the above quote erroneously attributed to Confucius in this particular instance.