“The real issue is not the number of hours we sit behind a desk but the energy we bring to the work we do and the value we generate as a result. A growing body of research suggests that we’re most productive when we move between periods of high focus and intermittent rest. Instead, we live in a gray zone, constantly juggling activities but rarely fully engaging in any of them—or fully disengaging from any of them. The consequence is that we settle for a pale version of the possible.”