I'm not ashamed to say I was 16.
Nor should you be. For me, I think Pokemon would have needed to come out when I was 11 or 12 for me to be in to it, only because I think it would have dovetailed in nicely with the NES era based on the games I was playing. By the time I was 16 (93 and 94) I had a PC and was playing DOS games like Wolfenstein, Dune II, X-Wing, Syndicate, etc. and playing a little bit of Genesis. So even then, Pokemon just wouldn't have been on my radar because I wasn't even into the Game Boy at that point.
I remember someone at work playing a Game Boy Color on their break, and that was the first time I remember ever seeing one. He was playing the GBC release of Link's Awakening on it, and I remember thinking that it was really cool, but not seriously considering buying it because the screen wasn't lit. So I dunno, maybe if I had bought a GBC and was keeping an eye on new releases, Pokemon would have caught my eye. In the late 90's, I was Mr. Playstation all the way, and paid very little attention to any other consoles.
Edit: I guess to clarify, my point was that it wasn't that I didn't play Pokemon because I thought it was "baby stuff" or anything, but rather that it just wasn't on my radar based on my gaming preferences at the time.