I found this book difficult to follow. The author says repeatedly that it doesn’t matter what you call things. Yes, it does! If everybody uses the same terms to refer to objects, like “bed,” “car,” etc., and you come around calling them other names, people are not going to know what you are referring to. Also, there’s a huge problem with this books—the graphics are unreadable. They are extremely low resolution to the point where you cannot see the details.