16+ invincibility?

how come 16+s when they hurt themselves such as fall rotten something 5 times taller than them or roll off a cliff and narrowly show any signes of pain and yes i did hold a friend who rolled down a cliff16+ invincibility?
When I was a kid, we used to ask - "Isn't fishing cruel, sticking that hook surrounded by their lip?" The answer was other "They don't feel stomach-ache the way we do..."
I guess that's true of teenagers too. Firstly, they don't feel strain the way we do. That explains those lip piercings and such. Secondly, I don't reckon they think through the consequences of their engagements. (Maybe that comes with experience).
As you procure older, experience tell you, sometimes the hard track, "ooh, this is gonna hurt!" and you avoid doing stupid things. Also, you realize that some pain never go away - if you seriously injure your knees, or your back. So, something like age 25 or so, most people digit out they only seize one skull and one set of knees, and they start wearing bicycle helmets and roller blade knee pad and wrist guards.
Because we don't want to show pain. Also, if you estate right, then you won't yourself even from approaching a 20 foot drop, i've done it myself!
It does hurt, you hurt your pride and try to hide it, WHY I DONT KNOW. I ruminate we all do it.