It is a good thing to remember no matter how old you are or how you apply it, to your personal life or your business life.
Frankly, I think the list pretty much squares with the genuinely happy folks I know, and the miserable folks I know ... the list squares with what they ain't!
I was over forty when I finally realized that almost no one was thinking about me one way or the other. I don't know why it suddenly dawned on me when it did but it was clear as day that it was absolutely true. That freed up my mind and relaxed me more than anything else up to that point.