Hens that's funny you should mention that as I was on an old school Facebook page last night, I am in my 50s now, and a mutual friend lets call her A was contacted on the open messages by another woman, B.
B said " oo do you remember me?!" smiley face etc and A said yes of course I do. It was all I could do not to butt in and say yeah and I definitely remember you you fucking bully, this woman and her little group treated me like dirt for 5 years my mum even died during that period and she just continued. If I couldn't give specific examples, she'd still be bully. I bet she would say the same as you. We have other mutual friends and they remember things differently too - we've talked about this and it does seem that school memories stay with different people in different ways.
To the bully what they said was just a joke, harmless teenage fun, or an offhand comment. But to the person on the receiving end it could be devastating. I think Me is right when she says "awareness is low when you're a teen".
Both my DDs have been bullied in school, my eldest is 16 and left the school in question 2 years ago but if she sees the girls responsible in the street she has a panic attack. Where Me and I differ is where she says "it says more about her than you if she held onto it for so long". That attitude helps bullies to prosper.
No you probably weren't and certainly aren't an awful person, but you clearly hurt that teenage girl's feelings and no one can tell her that she's not allowed to feel like that, or that she's somehow less of a person because she was upset. Its an interesting example and I am glad you raised it. I don't think its in the same vein as the controlling partners being discussed on this thread - is it another side of the same coin so as to speak?