Arthur C. Brooks's From Strength to Strength explores the challenges and opportunities of the second half of life, arguing that professional success based on "fluid intelligence" peaks early and declines thereafter. Brooks contrasts this with "crystallized intelligence," which grows with age and experience, suggesting a shift in focus is needed for continued fulfillment. He examines the impact of success addiction, the fear of decline, and the importance of cultivating strong relationships. The book proposes a framework for embracing this transition, advocating for a reprioritization of values, a contemplation of mortality, and a deeper engagement with spirituality to achieve lasting happiness and purpose. Ultimately, it emphasizes the power of building new strengths and finding meaning in life beyond professional achievements.