Mastery by George Leonard is a very compact book that is package full of lessons learned over decades of practicing Aikido. This is a book about understanding people and yourself, dealing with the plateaus and valleys, and staying motivated through it all because walking the path of mastery is worthwhile, even if you never get to the end. The wisdom contained in the book takes years to appreciate. I re-read the book at least once a year, and every time, I walk away with a new look on my practice and matches.