I was a bully when I was around 9 or 10 years old.
How did you bully others/
I pretended that I was a superhero, and I hurt a girl to fulfill my dream.
Even if it happened a long time ago, you shouldn't make excuses for your behavior. You should try to make sure you aren't bullying other people.
I like bullying people, it makes me feel good. Isn't it normal to be competitive and aggressive as we live in a competitive world?
There's a difference in being competitive and being a bully. You shouldn't harm others and make excuses  for it. It's really hurtful and it will be hard to establish meaningful relationships if you hurt others.