I was bullied in primary school. Kids (boys) from older grades took me as a target to call me all imaginative ways that can be taken to one meaning: you're ugly like hell.
It had lasted for two years until I barked back to one of them (something like "you'd not that beautiful yourself") and he never did that again. For weeks I was spending my evenings, inventing replies to their attacks not to repeat any and one by one I freed myself from them.
That taught me one thing: they attack weaker and if weaker shows they are not so weak, the bullies either run in fear or don't enjoy it any longer. I learnt to fight back.
That also left me with one thing: I'm ugly. Sometimes I cry after accidentally looking into the mirror. I have to prepare myself mentally to look at that face, or I react to it very negatively. When people on a street laugh at something, I always think it's me and my horrible face. For years I didn't allow photos being taken of me.
Someone may ask why I never told anyone (teachers, parents). The answer is simple: it never occurred to me to do so.