I'm 26 years old. How would I fit in there with high schoolers?
Just want to comment on this, because I can relate.
A couple days ago, in the same day, two completely different people who didn't know each other, when I told them my age, replied that I look 22-23 at best.
I'll be 30 next April.
Also, back when I was active as a Yu-Gi-Oh player, so for a few years from 24 to 26-27 give or take (can't remember the exact dates, my memory blows), my group was one guy a few months younger than me, and the average age of everyone else was 16-17, and I won't lie when I say I've had a ton of fun in those days.
I don't believe that being much older/younger than the rest of the group you're a part of is odd. It may be for a random observer, but if you're fine with it well, why not?
...though, to be honest, and regarding dating and relationship, I did cringe at a friend of mine who back then was almost 30 and dated a 16-year old girl (no foul play thankfully, but she WAS a minor).