I mean of course I hold grudges with like people at my school. Other teens are technically kids. I'm still never going to forgive the girl the outed me.
I've learned to forgive my parents for most things I didn't think was fair growing up but now that I have kids of my own it makes more sense why they did some of the things they did like limit what I thought were my freedoms. Kids don't always have good judgment just because they haven't experienced the world like adults have. It's a tough world, our job is to help guide you through it until you're ready to navigate it yourself.
I hold a semi-grudge against my 7th-grade math teacher (For the sake of protection I'll call him Dr. Oliver). He hated every student and constantly gave out detentions and complained about how stupid we were. Unrelated, one day I googled him and found out he was Mr. Universe 2018.
IDK, he never killed anyone. Though another thing about him is he spoke so weird he became the meme of the class even 2 years after he left. Probably because of the class, because no way he'd just go from [REDACTED] to Chicago like that.