Exactly because it doesn't make you respond in a particular way! It's unpredictable how you may react to past abuse. Many of the people who have suffered domestic violence later struggle with aggression and anger manegement. Many of the people who are manipulative, codependent, narcissictic etc. have suffered some sort of trauma in the past. They can be fake, bratty and unstable

Children who bully other children don't do it "just because it's fun"... There's a deep underlying reason why someone wants to humiliate or hurt another human being even if that someone is a child