It is true the more we learn, the more we know the vast amount we do not know.
On happiness: I believe it was Abraham Lincoln who said, in essence, "A man is as happy as he decides to be."
What about the aging process? Will I one day know less, remember less, but be happier because of it ?"
However, I also believe that "great things can happen late in the game." Who said that? Was it a quote from the movie, "Under the Tuscan sun?"