I think a lot of posters are on the older side (I'm 40). I firsted visited ENWorld back in my mid 20s, but I didn't post until quite a few years later. Which is not to say that there aren't any young people who post, just that from what I've seen, the majority of regular posters are on the older side.
The younger folks could be coming in to look for a rules answer (because a thread popped up when they Googled the question) or to check the news. I think Morrus actually said a while back that most people who visit the site don't post on the forum, or something along those lines.
Oh boy. 37 years. Two or three lunchtimes a week and most Saturday afternoons while at school. Twice a week at university. A long gap mid-life gap where it was one full weekend every two to three months. About once a fortnight for 3E, and once a week for all editions since then with some small gaps in the order of a month or two.
There's a reason I never type '/played' into the WoW console!