To be seventy years old is like climbing the Alps. You reach a snow-crowned summit, and see behind you the deep valley stretching miles and miles away, and before you other summits higher and whiter, which you may have strength to climb, or may not. Then you sit down and meditate and wonder which it will be.
To put yourself into a situation where a mistake cannot necessarily be recouped, where the life you lose may be your own, clears the head wonderfully. It puts domestic problems back into proportion and adds an element of seriousness to your drab, routine life. Perhaps this is one reason why climbing has become increasingly hard as society has become increasingly, disproportionately, coddling.
We seldom break a leg as long as we are climbing wearily upwards in our lives, instead we do it when we start going easy on ourselves and choosing the comfortable paths.