Miyamoto Musashi said, "To know one way is to know all ways." What he was referring to is that what it takes to follow a Way and get good at it is the same for all arts. I was reading Eugen Herrigel's Zen and the Art of Archery from Sensei's library. Zen and the Art of Archery is an account of Herrigel's training in Kyudo in 1924 under Awa Kenzo and depicts what it was like to be a student of a traditional Japanese art or Way before WWII. There is a marked difference in training and learning before and after WWII (I have a whole theory that I may write about another day). If you look into Awa Kenzo's life, it is eerily like O Sensei's and you can see many parallels in their teachings and approaches to their arts. I think Herrigel deftly illustrates how serious and strict teachers from an era gone by used to be. It is funny because when I read it, I could see so much of it in Sensei.
Zen and the Art of Archery is a must read for anyone who follows any art seriously.
If you want to get a PDF copy of the book: http://www.ideologic.org/files/Eugen_Herrigel_-_Zen_in_the_Art_of_Archery.pdf