Musashi's Mnemonics

I have recently had the opportunity to re-read the Book of Five Rings by Musashi and as usual have found some new things within it that I hadn't spotted before. For those of you unfamiliar with this treatise it is divided into five scrolls or books; the Earth, Water, Fire, Wind and Void scrolls and in each Musashi writes about different themes. The Earth scroll introduces his thoughts on martial arts and the Water scroll details basis principles such as where to look, guard positions, footwork, the grip and fundamental striking techniques. The Wind scroll discusses other schools and how his is better (vital for a Samurai seeking sponsorship or patronage but also quite believable) whilst the Void is a philosophical discussion of 'the zone' in a Zen context.
The thing that recently caught my attention was the Fire Scroll and the different headings within it. They are decidedly more metaphorical in nature, such as 'Holding Down the Pillow' or 'Mountain and Sea Changing' whereas in other scrolls they are 'Five kinds of guard' and 'procedures for the five techniques' etc. It struck me that Musashi was probably trying to come up with images that could be rapidly drawn upon in a fight, which let's face it, is not the best time to be recalling long sections of text! Couple this with the fact that Japanese script is highly pictographic and could use one or two characters to describe a complex concept and it's easy to see how Musashi used these techniques in his combat and teaching. It also ties in with some of the esoteric features of Mikkyo Buddhism and Zen, both of which include concepts of simple imagery or even gestures to evoke direct transmission of teaching.
There are numerous examples of these sorts of techniques (the modern word is mnemonics) in modern sport, for instance Jonny Wilkinson's entire approach to penalty kicking in rugby revolves around imagery and repeated memory. Mental imagery can also be used to prepare for situations and an athlete can evoke special trigger phrases to invoke a certain response, either a stimulating or calming one. Last night at the club I invoked one of these key phrases when I was stagnating in a fight ("Mountain and Sea Changing" - look it up, it's a good one) and it certainly helped me quickly re-focus. It is not hard to imagine Musashi using such techniques to enhance his already formidable prowess - another example of him being ahead of his time!