Anyone else find childhood favorites less fun now?

[Fawfulthegreat64]

Like, they are still nostalgic to play and all, but... I know everything there is to know about games like Mario 64, which I'll be using as my example here. I can play it now, but it just isn't the same anymore. There's no vast new world to explore, no mystery. It was so much more fun when I would have dreams about beating the game, unlocking new levels and of course the mystery of Luigi. Even though it was all fake, I always had fun being fooled by the "unlock Luigi" guides and trying to pull them off. Newer games like 3D World also don't feel the same even on the first playthrough. I think it might have to do with the "A to B" nature of it rather than just throwing you into a whole new world to explore.

Anyone have any similar realizations about games you enjoyed vastly more as a child?