Like the title says, when I was younger getting near the end of the game felt like I was really far.
For example, in Jak and Daxter, when I got to the red sage hut when I was a kid, God Damn did I feel like I was really far away from the start of the game and have travelled a long journey.
Now when playing it, I still have fun, but I find the game is lacking it's adventurous feel to it what made me love it as a kid, even though I could never complete it.
-
Because you grow up, understand the world, and know how things work. Reality is harsh and can kill the joy you have as a kid. "Ignorance is bliss." isn't meant to be a joke. That's why.