I got loads of memories of these games, even if I came into them a little later.
Despite being a big fan of Pokemon in its first year in America, with Pokemon Blue followed by the card game's first two sets, by 2000 I suffered some major Poke-burnout and just wasn't ready to commit to a new game. Looking back, I think it had a lot to do with just the sheer volume of new games, particularly RPGs, coming out at that time, and my interest was just elsewhere. Before I knew it, Crystal was released and I didn't even know any of the new Pokemon or have any idea what kind of new things were in store for Generation II. I ended up emulating Silver version probably around a year and half after it came out, but it wound up hooking me all over again. I never owned the actual cart, but I put more hours into this one than Blue version by far, and in general just "took" to Johto better than Kanto. Not sure if it was the new monsters or the more polished game design or what, but it left more of an impression.
The best memory was either going back to Kanto for the first time, or getting my first level 100 ever - my Furret. Yep, sweeping the E4 with my tube-sock monster was one of my big gaming accomplishments at the time. Iron Tail for rocks, Shadow Ball for ghosts, and Slash for everything else. If I'd of known Return was so good back then I probably would have used that, but I was all about the crits anyway.
I also remember being so confused on how durable Magnemites were. They were part steel now, which I think I was aware of, but everything I hit 'em with seemed to be "not very effective". They kinda replaced Geodudes as the new grand annoyance for me.