I was thinking about this the other day, actually. Nice idea for a thread!
Back when Pokemon first hit the US, there was less information about it than there is today. Heck, that was in 1998, wasn't it? I was about 11 years old! The internet wasn't quite so ubiquitous or reliable as it is today, and because of that, the entire Pokemon franchise was able to maintain an aura of mystique. This is no longer the case, of course. Now all you have to do to learn about the cards in a set or an aspect of one of the video games is punch your question into google. Pick from one of the thousands of hits and you're all set. Back in the day though, you had to learn about the games/cards by word of mouth, or you had to find a reliable site where you could read up on things- which wasn't always an easy task. Guidebooks were a lot more popular back then than they are now; there were tons of guides printed and sold concerning all parts of the fandom. It was an exciting time to be alive, so far as being a Pokemon fan goes.
These days, like someone said upthread, the magic is gone. Well, I wouldn't say it's gone, perse, but it is slightly diminished. There have certainly been trade-offs; it's very easy to get reliable information about cards/games these days, but a lot of the excitement and intrigue that surrounded the franchise when it initially launched has totally dissipated, making it less mysterious and a lot more commonplace.
Now, considering the passage of time, it's really no wonder that a lot of kids these days don't recognize the older generations of Pokemon. The older generations are harder to get in the newer games; quite often, you have to import them from your previous games- which younger fans may not have played. What's more, the older Pokemon made their debut in games that were on platforms that no longer have any relevance. Try showing a young kid an original GameBoy and they'll look perplexed. "You used to play games on that?" Modern kids don't seem to realize that video games haven't always been as glamorous as they are now. There was a time before the internet. There was a time when you'd be made fun of for playing video games after a certain age. Heck, there was a time when you had to stand next to your friends to trade Pokemon via a link cable! No wireless communication stuff! It really was a different age, and I don't think it's fair for us to expect young kids to understand. In time, TPCi will recycle the old Pokemon; I'm sure we'll get another remake of Red and Blue before too long, and newer fans will be able to acquaint themselves with the older Pokemon that way. But their connection with those older Pokes won't be like the connection that the older fans have with them. Us older fans had the privilege of getting to know them first.