Good topic to post.
As a kid, I was always smaller than people my age. Although I never had any severe issues with bullying, when I was in primary school, I was physically bullied for a short period of time. I guess I was a lucky one, as I didn't really do anything about it and it eventually went away. However, shortly after it did, I actually became the bully myself. From about my last year of primary to halfway through secondary, I bullied people myself. I'm not sure why I did it, now that I look back on it I regret it. Although I never hit people or did any physical bullying, I'm sure there are some kids out there who would look back and remember me as the kid who was always rude to them and hurt them emotionally.
My advice is to NEVER become the bully yourself. Even if you're angry that you were bullied when you were younger, I would advice finding some good friends or family that you could talk to about it. I know it's embarrassing and is one of those 'things,' but seriously. It's not cool to hurt people, physically or emotionally.