“Do nothing which is of no use.”
— Miyamoto Musashi
From 'The Book of Five Rings' (Go Rin no Sho), written in 1645 in Reigandō cave, shortly before Musashi's death. One of his twenty-one precepts on mastery.
On Ganryujima I arrived late, carved a sword from an oar, and killed the finest swordsman in Japan with one strike. He had the best blade. I had clarity. I won sixty-one duels not by strength but by removing everything unnecessary. Wasted movement kills. Wasted thought kills faster. Strip away what does not serve you. The unnecessary is what stands between you and what you are capable of.