Anne needed to express herself. Things became congested and sometimes even toxic in the annexe. Kitty, the diary, became Anne's only outlet. Anne's diary "Kitty" is a vehicle or lens which we are able to observe Anne's life. Anne is a compelling narrator for the way she provides a lens on Jewish life in Hitler-occupied Amsterdam. In many ways she shows how the average human being responds to repression on a day-to-day basis. Some scholars believe that “Kitty” refers to Anne’s prewar friend, Käthe "Kitty" Egyedi. Others believe that Anne borrowed the name from her favourite book series, Joop ter Heul, in which there is a character named Kitty.