The quote from Ian McEwan's "Atonement" reflects the idea that escaping into daydreams can have a significant cost. When one returns from these mental wanderings, they often find themselves confronting a reality that feels less satisfying than before. This disconnection from the present can lead to disappointment and a sense of loss.

This moment of awakening serves as a reminder that while daydreaming may provide temporary solace, it can ultimately hinder our ability to appreciate the present. The contrast between our fantasies and reality may leave us feeling worse off than when we began, emphasizing the importance of being grounded in our actual experiences.