The Happiness Project by Gretchen Rubin follows the author's year-long experiment to explore what makes people happier and how everyday habits can contribute to a more fulfilling life. Rubin examines different areas of life—including relationships, work, family, health, leisure, and personal growth—and experiments with practical resolutions designed to increase happiness. The book combines personal experiences with observations about habits, behaviour, and well-being, encouraging readers to identify what brings them greater satisfaction and meaning. It is particularly suitable for readers interested in self-improvement, happiness, habits, personal development, and creating a more balanced and fulfilling lifestyle.