"An oft-quoted story about Pablo Picasso is about the time he was hanging around an exhibition of his paintings in Paris. He was approached by a man who asked Picasso why he didn’t paint people the way they look. 'Well, how do they look?' asked Picasso. The man took a photograph of his wife from his wallet and handed it over. Picasso looked at the picture; then handing it back, said, 'She is awfully small isn’t she. And flat too.' We have to accept the fact that much of what seems real to us is governed by our own perceptions."
-as excerpted from here