I didn't do anything really "weird" by my standards, but my standards may go some distance further than might be normal today. We did do some kind of crazy and dangerous things, though. We lived in a new subdivision where there were a lot of empty fields and a lot of kids and we were always outside playing around when we weren't in school and the weather was good.
Our neighborhood had a lot of hills and to enter our street from the east you would be on a fairly steep downhill, then had to turn onto the street and climb back uphill to my house. I didn't like the work of pedaling up that hill, so I would ride my bike as fast as I could on the downhill, then sweep through the 90-degree right with as little braking as possible, so my momentum would carry me much of the way up the next hill. If a car had been coming out at the wrong place when I zoomed around that turn I would have been lucky to live. How it never happened I don't know. Oh yeah, in the winter the city would spread cinders on the streets, and then take forever to clean them up. It was like a layer of very fine gravel. I remember a few times in the spring feeling my bike drifting left at top speed and hearing the cinders as the tires slid through them sideways. Never went down, though. And no helmets either.
My grandparents lived on a farm and I had a lot of cousins so there was a whole other set of things to do when we got together there. For example, we could ride horses any time, but we decided we needed to ride a pig. I can tell you, first of all, the pigs won't put up with it. Second, if you ride a pig in the pig pen you will get bucked off into pig pen muck.
One day my grandpa had me load two cows and two calves in the '62 Chevy pickup and drive them up to the top of a canyon, where he had taken some more cows in the other truck. About a 30 minute drive, the last half unpaved, narrow and winding. I was up for it, because I had been driving that truck for a while. My younger brother and two cousins went with me and everything went fine. I was 13 years old. When my son was 13, well... I just can't imagine it.