An old Pink Floyd song includes the following lyric, which I love:
They flutter behind you your possible pasts,
Some bright-eyed and crazy, some frightened and lost.
A warning to anyone still in command
Of their possible future, to take care.
These lines provide a visual to an otherwise abstract — but important — idea: that the future holds many possibilities, but once set on a particular course of action, these possibilities close off.
Your ability to affect outcomes diminishes as you become invested in the decisions you’ve already made. The older you get, the harder it becomes to change course. Time runs out; “the future” shrinks; you’re left to contemplate what might have been.
Thus, as you age it becomes increasingly harder to change directions. Eventually, you run out of time to undertake major corrections. Where early in life the vector for your life was flexible, it embrittles as you grow older. You become set in your ways.
This is a challenge in a world in which change happens faster and more thoroughly than before — and in which people live longer. You must actively fight the urge to become fixed and brittle. It’s an ongoing struggle: The more you experience, the more invested you become in the things that have worked; things that feel comfortable.
Comfortable is for chumps. Your possible future needs ongoing care.