Classical martial arts are a very different proposition from what is usually taught as "traditional" martial arts in this country. If you'd like to take a look inside that fascinating world, this book is an excellent place to start. Systema has some notable differences from my tradition (kuntao silat), but a lot of the fundamentals are strikingly similar: you will re-learn how to stand, walk, sit, fall, move, and above all, how to breathe. A classical martial art is a fundamental transformation, and Major Komarov's book is one of the best I've ever seen at explaining some of the ways that transformation takes place.