Who wants friends over 30? I like to make friends with young people. In all seriousness, at 42 I really do prefer to hang out with 20-somethings because they’re fun.
Oh dear God, no. 20-somethings... have a bit of living to do before they're interesting. Don't get me wrong, being 20 is awesome. When you're 20. Because you suddenly have so much freedom. But when you're in your 40s, that's not that exciting any more. Well, at least it isn't for me. I've done the crazy things, I know how they end. I like friends with a bit more perspective.
And simply put, most people over 30 aren't going to be "like me" in the least. Most of them are family-minded, career-minded, or both. I'm just not going to have much in common with someone who's married and either has kids or is trying to have kids, nor am I going to have anything in common with someone who's trying to aggressively climb the career ladder.
The people I have the most in common with and see as peers are by and large slackers in their 20s, not people my age. I'm 33, and the disconnect between me and most people my age is really jarring... I see most people my age as having more in common with my parents than me (this was especially noticeable the last time I saw my cousins in person... they're only a few years older than me, but they act just like my mom did at their age, while I'm still a big kid... I really feel like most people of my generation are effectively of an older generation).