If you were born in the 70s or 80s, you missed one hell of a good time. If you were born in the 90s, by the time you were old enough to really go out in your own, the kids weren't doing that anymore, so you didn't miss out. If you were born in the 90s, what you did miss out on was becoming a complete retard by attending public schools.
Us Gen X's and older, we were free to roam because every other kid was outside too. We spent all of our time around people, learning how to make and be friends, and finding stuff to do. If we got into trouble we had to figure it out for ourselves if a friend didn't know what to do. It was all about being accountable for everything in your life, so you got to learn a lot by virtue of being in that environment.