I can still recall the feeling of my world literally expanding.

When I was very young I had my backyard. Nothing existed beyond it. Then I had my back yard, the alley and my neighbor's back yard two doors down. There was some stuff a bit farther away, but I only really saw it, never went there.

Then I was old enough to play on the entire block and go up to the friend's house at the other end of the block. I wasn't allowed to cross the street, but I did. It was exhilarating.

Then my world expanded to a five or six block radius, the neighborhood was huge. There were tons of kids. I knew every house, corner shop, everything. But there were still streets I couldn't pass. I had a vague idea where things farther away were - if only because I paid attention as we drove there... but for most purposes that neighborhood was life.

Then I was a teenager, and I was literally walking a mile away from my house to hang out at the town center or go to friends houses... I'd walk all over an area roughly 2 miles in diameter. I knew how to get around the city to certain key locations, though I'd never walk it (too far and too dangerous), but I knew it.

The way your world literally expands, and you create a network of paths and areas and maps in your head, was one of the best discoveries.