During the course of my career, I’ve encountered many things that have baffled me and roused my curiosity. I’ve taken a habit of immediately writing a book about those things that I don’t understand. When the book has been written, I understand something - but not nearly everything. So I move on to lecturing about the subject. Having given lectures for a few years I usually begin to experience an incipient understanding. At that point, I have already arrived at the next baffling theme, and so it all starts from the beginning. As I have written 27 books, and travelled around in the world giving lectures for decades, there seems to have been a lot which I haven’t understood.