Re-occuring dreams with old classmates?

So recently I've been having different dreams which all had old classmates appear in them. Generally the dreams weren't about school and I'd like to find out why they appear in my dreams all of a sudden. The thing is, it's not like they're classmates from my last years at school, but ones I haven't seen and haven't been in a class with for like 7 years. They include old classmates like old friends, just classmates I didn't know that well and even an old teen crush.

Is there any meaning behind classmates I haven't seen in 7 years all of a sudden appearing in recent dreams?