Julian Barnes said this quote

Mariac tells us about the books he's read, the painters he's liked, the plays he's seen. He finds himself by looking in the works of others. He defines his own faith by a passionate anger against Gide the Luciferian. Reading his 'memories' is like meeting a man on a train who says, 'Don't look at me; that's misleading. If you want to know what I'm like, wait until we're in a tunnel, and then study my reflection in the window.' You wait, and look, and catch a face against a shifting background of sooty walls, cables, and sudden brickwork. The transparent shape flickers and jumps, always a few feet away. You become accustomed to its existence, you move with its movements; and though you know its presence is conditional, you feel it to be permanent. Then there is a wail from ahead, a roar and a burst of light; the face is gone for ever.