In retrospect, my too-old phase really wasn't as long as I feel like it was. I drifted away from the series in 2003/2004 - I definitely remember playing Ruby, and I remember seeing ad spots in toy store newspapers for FireRed & LeafGreen. I have only the faintest memory of seeing Teams Aqua and Magma start to appear in the anime. In my head, it was a long time before my interest was reignited, but in reality, it was only a span of 4 or 5 years. In eighth grade, I recall seeing other kids in the library playing Diamond & Pearl on their DSes. I have memories of looking online and getting familiar with the new Pokémon, although I wouldn't end up getting a DS of my own until 2011, as a Christmas present. In the meantime, I had a friend who gave me his Game Boy Advance and his copy of Sapphire (because yes, I did unfortunately toss all of my own stuff), and that plus my eventual discovery of emulators was enough to tide me over until I was able to fully catch up.

I think I might've slipped in and out of focus in that 2008-2011 gap, but at that point, it wasn't out of any self-perceived supermaturity. My interest in specific hobbies has always worked on a rotating cycle. At any rate, I distinctly remember "coming back again" around the time of Gen 5, as if it'd been a bit since I last played a game on an emulator or seen news about HGSS being announced. I actually loved most of the new designs right off the bat, so once I did receive my DS, White was the first game I played out of the three I'd picked up (White, Platinum, and HeartGold), and that was like some kind of revelatory experience or something given how much I still love Gen 5, lol. Honestly, on a personal level, I would consider that my "true" introduction to the series, far more so than playing Red or Gold or Crystal back in 1999-2001 or Sapphire in 2008.

Also, while I can't say I remember it all with perfect accuracy, I don't think my drift was stimulated by peer pressure or that kind of thing - I don't think I felt like I had to meet anyone's expectations; I think it was more a result of self-evaluation, an internal sense that I was getting older and therefore should like more mature things because that's just, like, what you're supposed to do, right? I think there's an interesting paradigm there. Recalling that one C. S. Lewis quote:

“Critics who treat ‘adult’ as a term of approval, instead of as a merely descriptive term, cannot be adult themselves. To be concerned about being grown up, to admire the grown up because it is grown up, to blush at the suspicion of being childish; these things are the marks of childhood and adolescence. And in childhood and adolescence they are, in moderation, healthy symptoms. Young things ought to want to grow. But to carry on into middle life or even into early manhood this concern about being adult is a mark of really arrested development. When I was ten, I read fairy tales in secret and would have been ashamed if I had been found doing so. Now that I am fifty I read them openly. When I became a man I put away childish things, including the fear of childishness and the desire to be very grown up.”

It's like he says, it's normal and healthy for children to feel like they're evolving, and to want to be acknowledged as mature and taken seriously by others. So feeling like you've outgrown an interest or a hobby isn't necessarily a bad thing - certainly I don't still enjoy everything that I liked when I was younger. But I don't think the tendency to mock kids for "still liking" whatever subject is helpful. Shame is a valuable emotion, but only in the right context and proportionality. I don't think it has much business being in the neighborhood of innocent childhood hobbies.