What drives a person to seek revenge against another?

I would say it is caused by a combination of being hurt, from an initial action, (because revenge is a reaction) and anger (the cause of the reaction). Obveously its not easy to just counter act them because if you feel revenge you are already in a certain state of mind that is indulged in emotion and lacks reason. You have to have the ability to realize whatever caused it happened, and you may or may not know why it happened to begin with, or the persons intentions of said actions. Finding out these things could ease some of the emotions but rarely does i would say.

In the end it all comes down to letting it go and moving on with your life, dont let people effect you on that level, it gives them power over your emotions. Deal with what has happened and just figure out where is best to go from there, getting back at them only causes them pain and ruins any possibilities of an relationship in the future. Even if you dont care about interacting with them further there is no justice in taking an eye for an eye, rather by understanding thier actions and understanding that they are suffering from their own condition, I personally would feel sorry for someone who either seeks out to cause pain or hurt or seeks revenge as they dont even see what they are doing and how they are behaiving.

Anger,pride and hatred-the only cure is forgiveness,the release of a grudge. That can be surprisingly hard to do.

anger.the only thing I can think to curb these feelings it to not put such big emotional attachments to people and possessions