Is growing up (mentally) too fast a good thing or a bad thing?

I spend a lot of (or probably too much) time hanging out with much older people (mentors, older siblings, etc), and I enjoy being around them. And somehow, I enjoy it when they share their issues to me. (Work, money, etc)
I didn't realize about this, until I tried to talk to a friend of the same age about an issue I'm concerned about, and the only thing she said was, "Really? You worry about those kinds of stuff?"
Day by day, the more I realize that I don't enjoy hanging out with friends of the same age group that much. My friends are all wondering how come I know a lot about the current issues, especially politics, and I told them I watch a lot of news on TV and read the paper, and they said, "Really? You can stand that?"
An older friend told me that I really should keep hanging out with friends of the same age group as well, just to "keep me in the ballpark".

I like being a few pages ahead of my friends, but do you think it's a good thing or a bad thing? I appreciate your opinions. Thanks a lot