When I turned 40, I realized that everyone I had ever thought was smart knew and did everything that made them smart by the time they were 40.
And I realized that I was one of those smart people. I'm as much of an expert in my own fields as they are, or were, in theirs. What I thought was unobtainable skill and knowledge was only fortitude, attitude, and practice. When I turned 40, I was no longer in awe of anyone.
When I was younger, I never did anything truly ambitious because I thought I would never be as talented as those other people who did those kinds of things. When I turned 40, I realized that someday I'm going to think about doing something ambitious and realize that it's a younger man's game, not for someone old like me.
And so here I am, at 40, willing and able to do all of those things. No one else can do them any better than I can. And to think, some of you may be smart enough already to figure this out by 30. Or 20.
Now I realize why old people can be crotchety. They've earned it. By the time you're 40, no one else has the right to tell you what's best for your own good.