The diaries are a potent symbol not only of a young woman’s desire for uncensored self-expression but also of the exceptional trials and unlikely survival of one family. The diaries offer proof that, no matter how dire the circumstances, Miranda and her family—including non-blood-related members—have found a way to endure the disasters caused by the asteroid strike. They even find new loves, celebrate the arrival of new life, and manage to salvage some hope for the future. The diaries are highly personal to Miranda, but she is also increasingly aware of the universal themes they may express to a potential future audience. Miranda keeps her diaries private so that she can clearly express herself without fear of censure or rebuttal, but when her family leaves the town, she leaves the diaries behind for anyone to read. 

Early in the book, Miranda’s diaries offer her a private space of reflection and personal development in a world where the needs of the community often outweigh those of the individual. When she discovers that Matt has told his new wife, Syl, about her diaries, she becomes anxious: “When we got back home, I went up to my room and hid all my diaries in the back of my closet.