I knew, and it was an illumination - one of those things one has always known, but never understood before - that all sanity depends on this: that it should be a delight to feel the roughness of a carpet under smooth soles, a delight to feel heat strike the skin, a delight to stand upright, knowing the bones are moving easily under flesh. If this goes, then the conviction of life goes too. But I could feel none of this. ... I knew I was moving into a new dimension, further from sanity than I had ever been.