Does anyone hold long grudges?

Back in high-school, there was a guy who I really hated. He didn't bully me or I didn't bully him but we just didn't really get along. I left high-school over ten years ago now and I forgot about about my deep dislike for him. I ran into him before the lockdown began and my hatred for him has come back. I'm trying to understand why I feel that way because I've never been that kind of a bitter person before.

It's got me thinking, do any of you guys still hold grudges which have lasted a long time?