I'm 17 now, and I've been dreaming of a 3D game since I got my first Pokemon game, Emerald.
And then I played Pokemon XD Gale of Darkness, and I realized that 3D battles were possible, and I saw how amazing and engaging they looked, and they were so much fun! I actually felt like I was part of the game. I felt sad that I couldn't catch Pokemon properly though, or fight the Elite Four, or battle Gym Leaders.
I bought Diamond, and it was fun, but I didn't finish it. I couldn't go back to those boring sprite battles anymore. The mechanics were great and all, but you can only become engrossed in a game so much when everything is so unrealistic. The pokemon in XD felt so REAL, and these Diamond Pokemon didn't. Besides, my favourite Pokemon, Lucario, looked so ugly as a sprite!
I didn't buy any more Pokemon games or play any more games after that.
And then the announcement for X and Y came out. I totally FREAKED OUT! I was extremely happy. I wasn't expecting a 3D game to ever come out as a mainstream game, and it caught me totally caught me by surprise. I had long since sold my DS Lite, and I hadn't played Pokemon for 4 years, but my interest in it had remained a little.
I am literally going to buy a $200 3DS console for the sole reason of playing one of these games. I've been waiting for 3D for WAY too long, and now it's finally coming! :D