I'm sure the guy in the wheelchair video knows the consequences of what could happen probably better than any of us.
It's a zest for life and excitement.
Would I let my kids do it? No. But now that they're adults, they can make up their own minds.
When I was younger, I did a lot of things that could seriously mess you up. Motorcycles. Rock climbing. Skin diving (now called free diving). Lifeguarding on a whitewater course.
I can think of a lot of things where young people get hurt. Skateboards, roller skates, cheerleading, gymnastics, motocross, BMX bikes, you name it.
We used to play on rope swings at the lake I grew up on. Saw some serious injuries there. Also saw a guy run out into the water at a public beach, dove in and snapped his neck because the water was only a foot deep. He became a quadriplegic that day. Another guy dove off of a bank in that same lake and hit his head on a pipe. Another quadriplegic.
You can hurt yourself so many ways it's about impossible to guess when it will happen. My next door neighbor fell down her basement steps and broke her neck. She passed away. A coworker of mine's husband did the same thing, but it took him several weeks to pass away from the injuries.
While I no longer partake in those risky activities, I still take my laundry down to the basement.