"Off the rails". I love that term.
When I was a kid (in the 50s), we rarely played outside with adult supervision. We wandered aimlessly, learned a lot, and had a blast. The things we did.
My kids never got to do that and never even seemed to want to. Their childhoods were so dull compared to mine, but they seemed happy about it. I think we did about 500 times as many things as they did. When I tell them stories, their eyes get real big. Like the time we were out riding bikes and ended up near a tornado and got blown across a freeway by 100 mi/h winds. Mom asked, "What were you guys up to?" The stock answer was, "Oh, nothing much." Or the time my friend got picked up hitchhiking after his bike got stolen by the guy who wanted to... No. No more stories. Maybe tomorrow. Time to go to bed.
I guess it was our fault that they didn't get to wander.
When I was a kid, and even though a girl, I was always out playing, or wandering about. I'd take a book, and I had a favorite tree to climb in an empty field. I'd climb up, perch in the crook of the branch, and read. One of the differences then as versus now, is that most women were stay-at-home mothers. Everyone in the neighborhood kept watch on everyone else's kids. It was hard to get into too much trouble or danger, as there was always a home to run to where someone would be home, and the whole neighborhood was watching your behavior, as well as watching over your safety. And you actually got punished or yelled at, by anyone's parents, not just your own, and your parents all backed each other up, rather than try to sue each other. And yes, there were some creeps around (like Peeping Toms), but they were much fewer in those days, and when caught were actually locked up. I'm so glad I was brought up in the late 40's and then the 50's when young. My teen years were in the 60's, and that's when things started getting dicey.