As we grow older we become more risk averse. This is usually noticeable when we look at our kids and watch them leap out of trees, jump off high diving boards, or take to their skateboards; things we used to do without a second thought when we were their age.
In my early 20s a bunch of friends and I took up sky-diving. Even with thumping adrenaline and bravado, there was still a moment of hesitation as I as I stepped out of a perfectly good aircraft. But as I clutched the wing strut and let go to plunge earthwards, nothing was going to stop me.