I’d say moreso with emotional maturity than with advancing age. Though that may be true also.
Cultivating emotional maturity has a tendency to peel back layers of deeply hidden false beliefs like peeling an onion. I happen to believe that beneath those layers is, within each of us, a magnificent god-being that progressively reveals itself as we do our emotional “work”.
And when the light of that revelation begins to seep out of the inner darkness, gratitude and joy just naturally follow.