Although I have seen this quote attributed to others I know it from Herman Melville in Moby Dick.
“To know how to grow old is the master work of wisdom, and one of the most difficult chapters in the great art of living.”
It’s no secret. Eat healthy and exercise daily. In other words: “Do as I say, not as I do!”
“Piece of cake!” I am full of useful quotes, or something, today.