The longing to behold this pre-established harmony [of phenomena and theoretical principles] is the source of the inexhaustible patience and perseverance with which Planck has devoted himself ... The state of mind which enables a man to do work of this kind is akin to that of the religious worshiper or the lover; the daily effort comes from no deliberate intention or program, but straight from the heart.
Your good mother tells me you are feeling very badly in your new situation. Allow me to assure you it is a perfect certainty that you will, very soon, feel better - quite happy - if you only stick to the resolution you have taken to procure a military education.... On the contrary, if you falter, and give up, you will lose the power of keeping any resolution, and will regret it all your life.
Have fire and spread all over. Work, work. Be the servant while leading, be unselfish, and never listen to one friend in private accusing another. Have infinite patience, and success is yours.
Nobody trips over mountains. It is the small pebble that causes you to stumble. Pass all the pebbles in your path and you will find you have crossed the mountain. The mind does not create what it perceives, anymore than the eye creates the rose.