why do we need to tell the story sarah's key?

Remembrance of history is an important point. The plot that parallels between Sarah and Juliet is Juliet’s knowledge and want to learn more about the history of the apartment Juliet lives in. Juliet researches and feels guilty for what happened with Sarah, and she learn more and more about her life and the lives of her loved ones. William, Sarah’s son, did not want to learn about his mother life in the beginning. He later changed his mind, as he realized how important it was, and how big of an impact the history had on the way things are in the present day.