Revenge

Normally, people would seek revenge when something that other people has done to them hurt them to an extend that they couldn't stand it. For example, money, love and reputations. These would be the most common reasons for people to seek revenge on other people. Some minor reasons could be from insults, pranks, or jokes. Some people may take pranks and jokes really seriously and get angry to decide to revenge. And in movies, there are often parts where someone really close to a character, his/her mother, lover...etc. gets killed or hurt, the character changes into a different person and decides to seek revenge. If people get obsessed to vengeances, it'll lead to a tragedy because to seek revenge means to do something bad to the person that hurt you. Doing anything that hurts other people isn't a good choice in the first place and if you get obsessed in doing it, which means that you'll be doing bad things over and over again. Doing bad things all the time could be considered as a tragedy.