This book collects the lifelong research on boredom by American psychologist Augustin de la Peña (1942-2021). It focuses on the experience of boredom-and other similar states, including ennui, melancholy, laziness, interest, attention, and entertainment-and its associated behaviors. Offering an interdisciplinary chronicle of boredom, from Antiquity to the present, special attention is paid to its daily experience as a ubiquitous phenomenon that informs cultural and political actions that continue to shape our society. Dr. de la Peña describes the obsolescence of the Western Commonsense View of Reality to propose a Developmental Psychophysiological Approach to Reality, reconceptualizing boredom. The book theorizes the condition as both logical and emotional, an axis that has defined the sensibility of the modern era. This is a volume edited posthumously by Josefa Ros Velasco and Christian Parreno in homage to Augustin's work and his invaluable contribution to the establishment of the field of boredom studies.