How did Daniel comfort Elisabeth when she could not remember her father's face?

Elisabeth was having trouble sleeping because she could not remember her father's face. When she told Daniel, he told her that it was all right and even good to forget. He said that forgetting was important, and that they did it on purpose. Forgetting gave people a rest. He told Elisabeth that people had to forget or they would never sleep again. Then he told her how he imagined a bird sleeping next to him when he forgot something.