HOW ANGELS SLEEP. Unsoundly. They toss and turn, trying to understand the mystery of the living. They know so little about what it's like to fill a new prescription for glasses and suddenly see the world again, with a mixture of disappointment and gratitude ... Also, they don't dream. For this reason, they have one less thing to talk about. In a backward way, when they wake up they feel as if there is something they are forgetting to tell each other. There is disagreement among the angels as to whether this is a result of something vestigial, or whether it is the result of the empathy they feel for the Living, so powerful it sometimes makes them weep. In general, they fall into these two camps on the subject of dreams. Even among the angels, there is the sadness of division.
Nicole Krauss, The History of Love
angels, dreams, sadness