This Life Kit podcast episode interviews Gretchen Rubin, a writer specializing in happiness, habits, and human nature, to explore how self-knowledge contributes to happiness. The interview covers four key areas: understanding personal preferences (morning vs. night person, need for accountability, etc.), identifying one's "Four Tendencies" (Upholder, Questioner, Obliger, Rebel) to better manage expectations, utilizing self-awareness to build happier habits, and recognizing that happiness comes from small daily actions as well as larger life changes. Rubin emphasizes that there's no one-size-fits-all approach to happiness; understanding your tendencies is key to finding what works for you. For example, she explains how "abstainers" find it easier to eliminate temptations entirely, while "moderators" prefer a more balanced approach. The episode offers practical advice for listeners to improve their well-being by focusing on self-understanding and consistent, even small, positive actions.