Why do I keep dreaming of a specific person from my childhood?

I moved schools 5 times when I was a kid but I often have dreams involving one particular girl from one of my first schools and our class mates from said school often join in the fun too.

We were "frenemies" as so many girls are at that age (10-14) and I guess there was a lot of strong feeling around her. But it's years later, why does she and our classmates keep popping up all over the place?

Could they be bringing me back to that time in my life when things were very turbulent? (family and home issues?) Or do I have some unsettled beef with said girl that I need to work out?

Thank you