I found my first year a bit lonely. There was only one other mature student in my cohort, and TBH she was a bit of a pain (even by mature student standards!). The younger students didn't seem to know how to talk to me and were embarrassed when I tried to chat. But hey. For most, it was the first time they'd been in a sort-of social situation with someone their parents' age. Before that, 'those' people were bosses, teachers, parents etc, who were out to judge them and tell them what to do. I spent a year carefully making sure that I did no such thing. I heaved a sigh and joined Facebook at the end of that year, as it seemed to be how there were mainly communicating. Some of them were happy to chat online when they wouldn't in person. By the start of the second year I was part of the furniture and included in the chat and banter with everyone else.
Yes, I asked far too many questions. Unfortunately I spent 20+ years in jobs where I was constantly having to learn new things on the fly, and I wouldn't have survived unless I kept asking questions. It's a habit which I suspect comes with age for many people. I also answered too many questions, as it irked me when a lecturer asked a question and the rest of the room just sat there blankly. It could descend into a time-wasting staring match when neither party would back down!
As for being "too enthusiastic" - guilty as charged! But then I had a whale of a time and came out with a First plus twenty extra credits (admin error meant that some of us accidentally did one more unit than we should have in the second year).
I certainly wasn't better than the younger students. Going in with the attitude that somehow mature students should be treated differently, is a hiding to nothing. In a standard uni, you're signing up to enter a largely 18-22 year old's world. Adapt and survive. Who knows - that process in itself might actually be fun and stretch you as a person? It's all part of the learning experience. I would've hated to come out the same type of person as I was when I started.
Personally I loved the energy and enthusiasm of the environment - it rubs off if you let it!