What are the motifs in The History of Love by Nicole Krauss?

Personal histories of love is a recurring idea. It is only fitting that the title of the book, as well as the book-within-the-book, is one of the key ideas. Each of the main characters dictates their personal history of love through the course of the book. It is seen in Leo's promise to never love anyone other than Alma Mereminski Moritz, in David and Charlotte Singer's relationship, and in Zvi's love for his wife Rosa.