I've been to two class reunions (10 year and 20 year) and what I can tell you is that the social barriers that existed back during high school aren't really there. People mostly chat about what they've been doing with their lives, their significant others, jobs, kids if they have any. I have found that there's really little chat about things that happened during school years and it's mostly about catching up with life as adults... and it's interesting to see what became of some people. There are definitely some surprises that you wouldn't expect!

I hope that helps ease your tension about it.