I would like to add another one to Ditter's list.
We played sports, all by ourselves, with no adult coaches, umpires, or spectators. We made and enforced the rules, settled disputes, chose up sides, without ANY HELP from grownups. If anyone's parents had sat on the sidelines, cheering them on, we would have thought they were certifiably insane.
Kids these days miss out on all that. They can't do anything without an adult to tell them what and how to do it.
And yes, I was the one who was always chosen LAST for the team. And I survived.