From Strength to Strength: Finding Success, Happiness, and Deep Purpose in the Second Half of Life

by Arthur C. Brooks

Instead of denying change in your abilities, you can make the change itself a source of strength.

studies show that people who have chased power and achievement in their professional lives tend to be unhappier after retirement than people who did not.[21]

Translation: When you are young, you have raw smarts; when you are old, you have wisdom. When you are young, you can generate lots of facts; when you are old, you know what they mean and how to use them.