Before I start painting I have a slightly ambiguous feeling: happiness is a special excitement because unhappiness is always possible a moment later.
I feel ever so strongly that an artist must be nourished by his passions and his despairs. These things alter an artist whether for the good or the better or the worse. It must alter him. The feelings of desperation and unhappiness are more useful to an artist than the feeling of contentment, because desperation and unhappiness stretch your whole sensibility.