I'm sorry this happened to you growing up. I think that experiemce did give you an understanding of racism in that, you were taught younger than most white kids that there are races in this country and that has a meaning. That said, many white people told me similar stories of being bullied by the Black kids at an all Black school(some use it as ammo that reversed racism exist). I believe for a lot of white kids it's the first, and possible only, time they're explicitly racialized, but it's regular school bullying for being noticeably different hence the context doesn't leave the school setting.