I'm 27 and got back into the hobby about 2 years ago.
As a kid, we mainly collected the space (M-tron, Blacktron, Ice Planet, and Spyrus) and castle (Black Knights, Dragon Masters) themes. We didn't have a lot of money, but usually could count on a set or two around birthdays or Christmas.
I quit building once I moved away to college, and while I didn't even really build all that regularly while in high school, I did dabble a bit here and there with the occasional spaceship or castle. Even while in college, when I'd come home for Christmas, I'd usually spend a day or two in the basement building the biggest, multicolored castle my sibling's collection could support.
The light really came on when my mom sent me an article about a guy who was building a scale replica of the Ohio State football stadium. In the article, he mentioned some crazy site called "Bricklink", which sparked my curiosity. A few clicks later, and I was amazed at what people were building in the online community, and what an amazing resource this new (to me, anyway) website Bricklink was going to be. Once I found Classic-castle, I was all-in, hook, line and sinker. I never dreamed as a kid that people actually built "color-coded" castles and concepts such as SNOT were an added point of interest.
My main AFOL/TFOL influences these days are people like Mark of Falworth, Fraslund, DC, Siercon & Coral, Ecclesiastes, Blake Baer, Eklund, and many others. There really are too many talented builders out there to name them all.
One thing that I'm really proud of is the LCC program that we've started over in the Stories forum. We are up around 125 members, officially, though probably more like 50 who are really active, but it's still a blossoming project and it has been really cool to be a part of the development of it. Hopefully it will be something that holds the interest of a lot of KFOL/TFOL/AFOLs, and keeps them interested in the hobby. Maybe someday they'll look back and point to it as one of their major building influences, which I think would be a really cool thing.
Anyway, I'm glad to be back, and I'm now regularly bombarded by links to cool Lego stuff that my friends see, because they know that I'm the "Lego guy" and that I'll find them interesting. It's kind of funny to have a tag like that, especially when I visit home and the first thing people ask is, "so, how's the Lego thing going?"