All of these obvious questions are quite well addressed by the actual book in question, as would be expected from a serious and respected work, since its entire

All of these obvious questions are quite well addressed by the actual book in question, as would be expected from a serious and respected work, since its entire raison is to explain why this seemingly counterintuitive idea does in fact make sense and fits much evidence. Here's a simple intuition pump to get you started: Do you think that you don't hear voices? Do you know about the concept of "internal monologue?"