Imagine 100 high school-aged teens – boys and girls, city and suburb dwellers, “heavy smartphone users” and regular users – disconnecting from their smartphones for one whole week. It may sound fictional, but this exactly is what occurred as part of a fascinating experiment that we recently conducted, which serves as the basis of this book. For a long and challenging week, these teenagers documented their experiences in personal diaries, and described them in personal and group interviews. They described their physical and psychological feelings about life without their devices, the effect that disconnecting from their devices had on their social life, their family life, and their management of time and routine tasks. The participants described how their lives looked without a smartphone in school and during their free time, how they missed their device and felt its absence upon waking in the morning and in the moments before falling asleep, and how they even felt it in their dreams, which were filled with longing for the digital friend that had been taken from them. This book provides deep insights into the role of the smartphone in the daily lives of teenagers, and the culture of “cellphones natives,” members of Gen Z. The book offers a new point of view on questions occupying researchers, parents, educators, and professionals: how and why did the smartphone become the dominant medium of communication in the lives and culture of teenagers? How does it shape and influence their daily lives? Can the relationship with the smartphone really be characterized as dependence and perhaps even as an addiction, as many claim, or is it relationship of a completely different nature? In a world full of technology, the aspiration to better understand teenagers and even ourselves requires acknowledging the ways in which these technologies are woven into every moment of our daily lives, for good and for bad.