Today my class learned about bullying.
My teacher gave each student a fresh sheet of paper, and asked us all to crumple it up in a ball. She then asked us to unfold our paper and try smoothing out all the wrinkles, to try and make it look brand new. The only problem? It was impossible to make that sheet of paper look brand new. The damage was already done. That's exactly how a bullied kid feels. You bully them, then feel bad, and when you try smoothing things out with them? No. The damage was already done, and you left permanent scars on them forever.
Don't bully. You never know someone's story unless they tell you.