I have it, too, and really like it. The only thing i don't like about it is how it's formatted. It gives a bunch of questions, and then the answers at the end of each chapter.
I'd really prefer that the answer be BELOW the question. Petty? Maybe! But it bothered me so much that I considered sending that suggestion along to the publisher.
Unless you're quizzing yourself, it's a pain to keep flipping pages. I just got the book to LEARN interesting facts, not to quiz myself.