Angela Duckworth’s Grit: The Power of Passion and Perseverance is a bestselling exploration of how passion and long-term perseverance, rather than innate talent, drive success, often summarizing key concepts like the "grit equation" where effort counts twice, and the "four traits" of gritty individuals, which are interest, practice, purpose, and hope. The book also introduces the "hard thing rule" for cultivating personal and professional endurance. [1, 5, 10, 11, 13, 14, 24, 29, 38]