'When you look at a white wall you will realize that it is neither white nor bare. If you are on your own for a long time and get used to being alone and are more or less trained in loneliness, then you begin to discover more and more in places which, for normal people, are (essentially) bare. On the wall you discover cracks, fine cracks, uneven patches, vermin. There is a tremendous movement on the walls. – in actual fact the wall and the page of a book completely resemble one another.'