Why are people who are violent on campus irritable?

Someone asked me to answer, so I just said a few words. Write it at the beginning. You must remember that school violence only blinds your ability to love others and accept love, but never deprives you of these abilities. I have never been treated by school bullying, and even many bullies will respect me, but ironically, I still can't stop school bullying from happening around me. In junior high school, there was a chubby boy in my class, and my primary school was also a junior high school. There were faint signs in elementary school, and everyone didn't know why they bullied him naturally. To make matters worse, in junior high school, including teachers, all participated in bullying him. The teacher took out his composition, misinterpreted his meaning and made everyone laugh. Students beat him and scolded him after class and threw away his schoolbag and books, but he was really strong and he resisted. However, it often brings more campus violence. Even if he was bullied, he seldom told his family that he was bullied at school. Once he was beaten and bleeding, he invited his parents from home. He should punish those who beat him. However, near the entrance examination, his parents decided not to let the school punish his "top students" for his future, and those "top students" did not thank their sons as always. I feel guilty that I just didn't participate, but I didn't stop it. Looking back now, I didn't bully him because I didn't want to bully him. I didn't help him because I was afraid of being bullied ... After the senior high school entrance examination, we went our separate ways and occasionally met him at school. He saw me say hello and told me a lot. He didn't discuss bullying in junior high school with me, and naturally he didn't blame me. I think I must have been relieved, he told me. He has friends now (a few people didn't bully him in junior high school, but they weren't friends), and his teachers value him very much, and his academic performance is not as bad as before. As expected, he was admitted to a very good university in Shanghai, but this is what really made his fate terrible. Junior high school bullied him the most, and the top students who were "protected" by their parents were also in this university.