Forget your sadness, anger, grudges and hatred. Let them pass like smoke caught in a breeze. Do not indulge yourself in such feelings.
Any place we can breathe, we can do Ninjutsu.
Move with your feet, the hands will follow.
You must throw away your bad habits to get good.
When weak or injured always continue training as you should always be able to adapt in any condition.
Those who desire only techniques will never understand this art. It is everything beyond that