A man of genius has been seldom ruined but by himself. Samuel Johnson
The crucial discovery was made that, in order to become painting, the universe seen by the artist had to become a private one created by himself. André Malraux
No man is so foolish but he may sometimes give another good counsel, and no man so wise that he may not easily err if he takes no other counsel than his own. He that is taught only by himself has a fool for a master. Hunter S. Thompson
He that falls by himself never cries. Turkish Proverb
He who works by himself does the work of three people. Italian Proverb
I renounce the friend who eats what is mine with me, and what is his own by himself. Portuguese Proverb