I used to take the train from the city I lived in to the city my friends live in when I was around 10 (was about a 20 min train ride).
I'd stay out until the wee hours of the morning when I was 14 with friends doing things no 14 year old should be doing.
I used to see rated R movies on a regular basis when I was under 10. I can recall my Dad dropping me off when I was 12 to see one of the Nightmare on Elm Streets.
Lawn Darts.
BB guns.
Toy guns that looked (more) like real guns.
Took 4 wheelers (ATV's) out into the woods without any adult supervision.
Drove a motorcycle full time at the age of 14 until I got my first car at 16. It was a Suzuki GN250. If I was going down a really long hill I *might* be able to get it up to 90mph.
Drove other people's cars at the age of 15 for the detail service I used to do at my Dad's car wash he owned at the time. I'd ride my motorcycle to where the person worked, leave my bike there, get their keys and drive it back to the car wash to detail it, then I'd drive it back when done. I told people every time that was was only 15 but no one ever cared. I learned how to drive a stick shift really quick by doing this.
Took my parents boat out onto the lake we lived on to explore around all the time. This wasn't a small lake either, it crossed state lines even. My brother and I would take the boat out to this one island and camp on it on a regular basis, we'd have bond fires, shoot bottles with our BB guns, set off fireworks. All sorts of fun stuff. Now that I think back to it, I have no idea what my parents would have done if they *had* to get to us since we had the only boat they owned.
I guess my parents were very trusting of us, I'm thankful for it though, I had some good times
I also was probably corrupted at an earlier age than most also since I had a 3 year older brother that didn't filter me from his discovers

Alcohol, pron, cussing, etc..