Sure, some parts are out of date. But so much of it remains true even today. There's a saying about lectures that say that the best questions a lecturer can get are the ones answered by the very next slide. Well, that is exactly what happened to me, again and again, with the chapters of this book. Most amazingly, a question a friend raised in a discussion we had about chapter 8 was answered by the very first sentence of chapter 9. Can't be better than that.