"Specialise!" is the advice often given by career advisers, school teachers and the like. David Epstein takes the opposite position: In an ever more specialised, highly complex world, it pays to have good old-fashioned broad common knowledge in as many areas as you take interest in, both in terms of intellectual curiosity and professional success. To have a decent grasp of various aspects of life means to be able to discern the links between them, thus developing a better understanding of how our world works and what drives events as they unfold.