There is nothing outside of yourself that can ever enable you to get better, stronger, richer, quicker, or smarter. Everything is within. Everything exists. Seek nothing outside of yourself.
-Miyamoto Musashi
It is good to face challenges in your youth. He who has never suffered will not sufficiently temper his character.
-Yamamoto Tsunetomo
Good medicine is bitter to the mouth, but has an effect on the disease. Faithful words hurt one's ears, but have value for one's conduct.
-Takeda Nobushige