I believe that it may happen that one will succeed, and one must not begin to despair, even though defeated here and there; and even though one sometimes feel a kind of decay, though things go differently from the expected it is necessary to take heart again and new courage.
For the great things are not done by impulse, but by a series of small things brought together. And great things are not something accidental, but must certainly be willed. What is drawing? How does one learn it? It is working through an invisible iron wall that seems to stand between what one feels and what one can do.
- Vincent Van Gogh in a letter to his brother, Theo.