I agree with the all the previous posts. I went back to uni at 31 to study medicine. I was a bit paranoid about it and thought it would seem weird, but I do love going out and having fun.
I just thought screw it I have every right to be here and enjoy myself. But I soon realised I did not need this attitude at all. No one notices your age, they notice if you are a good person and fun. Heck I used to always throw parties at mine and organise nights out.
Seriously get involved you are going to make great memories with some great people, enjoy.