Real experiences have a way of teaching that reaches past reading about experiences in a book.
For example, I've tried to learn the metric system from math books for most of my life. Basically this has resulted in my having a hazy, at best, acquaintance with the subject. I'm living the metric system every time I ask directions, drive to my destination or purchase grocery items. An entire book on one subject affords far more retention than a short paragraph in a textbook. Living books have facts in them just like any textbook would but they also feature people living through ocean exploration, wars, scientific discoveries, etc.