" From somewhere came the idea that there were many different levels of sleeping, of unconsciousness, and therefore of awakening. In the midst of this pleasant woozy calm - warm, pleasantly swaddled, self-huggingly curled up, a sort of ruddy darkness behind the eyelids - it was an easy and comforting thing to contemplate the many ways one might be away, and then come back. "

― Iain M. Banks , Surface Detail (Culture #9)