No man is invincible, and therefore no man can fully understand that which would make him invincible. Even with complete and thorough study there is always the possibility of being defeated and although one may be expert in a particular form, mastery is something a man never stops seeking to attain.
Miyamoto MusashiFourthly, the way of the artisan. The way of the carpenter is to become proficient in the use of his tools, first to lay his plans with true measure and then perform his work according to plan. Thus he passes through life.
Miyamoto Musashi