It is also about his journey. I recommend it to you as Aikidoka. At the very end, he quotes a Buddhist Lama. This resonates for me both on the mat and in my life. Perhaps it will ring true for you as well.
Do not believe it because it is written in a book. Do not believe it because it has been handed down for generations. If after observation and analysis, if it agrees with reason and can benefit one and all, then accept it and live up to it.