I recently re-read The Book of Five Rings by Miyamoto Musashi. These passages stuck out for me:
The long sword seems heavy and unwieldy to everyone at first, but everything is like that when you first take it up: a bow is hard to draw, a halberd is hard to swing. In any case, when you become accustomed to each weapon, you become stronger at the bow, and you acquire the ability to wield the long sword.
“Mountain and sea” means that it is bad to do the same thing over and over again. You may have to repeat something once, but it should not be done a third time.
When you try something on an opponent, if it does not work the first time, you will not get any benefit out of rushing to do it again. Change your tactics abruptly, doing something completely different. If that still does not work, then try something else.
Thus the science of martial arts involves the presence of mind to act as the sea when the enemy is like a mountain, and act as a mountain when the enemy is like a sea. This requires careful reflection.
When fighting with enemies, if you get to feeling snarled up and are making no progress, you toss your mood away and think in your heart that you are starting everything anew. As you get the rhythm, you discern how to win. This is “becoming new.”
Anytime you feel tension and friction building up between yourself and others, if you change your mind that very moment, you can prevail by the advantage of radical difference. This is “becoming new.”