Hagakure on training

"A man who gains a reputation due to a technical perfection in martial arts is an idiot. Out of his foolishness he focuses all his force on one thing and in order to succeed at it forgets to think about anything else. Such a man is not properly prepared."

"A man's training is endless. Sometimes, you start to feel that you have reached perfection at something, so you stop doing what you were doing. Whereas, he who wishes to reach perfection must always remember that he is very far from it. Only he who is not satisfied with just being an achiever and always striving for new achievement can consider himself to be a great man."

from Hagakure ("Hidden in the leaves") by Yamamoto Tsunatomo 1716