The document discusses seven keys to living an optimistic and happy life: 1) Have a purpose, 2) Take action and be bold, 3) Honor yourself, 4) Forgive others, 5) Forgive yourself, 6) Have gratitude for all of life, and 7) Be of service to others. The author argues that being of service to others, whether through raising children, caring for others, or developing products to help people, is perhaps the single greatest secret to happiness, as it allows people to live beyond themselves and leave a lasting positive impact. Choosing a life of purpose that incorporates service to others can lead to great satisfaction and lasting happiness.