As Anne goes through puberty, we see her becoming more mature, thoughtful, and more aware of her body. Her confinement forces her to struggle with many of the questions of adolescence by herself, since there are no other girls her age with whom she could share her experiences. Thus, the diary becomes an important tool for Anne’s self-discovery and maturity. She starts to feel disconnected from “the Anne of last year” as she looks over past diary entries about her mother, which she now considers the product of her immaturity and girlish moods. Anne has a record of all of her private yet indignant temper tantrums, which allows her to see how much she has changed in such a short time. Writing in the diary allows Anne to express her unkind and indulgent emotions and explore her own personal desires in a way that will not hurt anyone else. Anne’s candor caused Otto Frank to cut many parts of the diary in its original publication. Anne’s judgments, though at times cruel, are an important aspect of her personality and her experiences. Anne’s written outbursts provide a full sense of who she is and how she changes while she is in the annex.
With her diary as her only confidant, Anne misses both her female and male friends, and she thinks often of her love, Peter Schiff. She is drawn to Peter van Daan, since he is the only young man sharing her experience. Anne is naturally curious about Peter because he is a teenage male, and as a girl in puberty, she is fascinated by his body. Anne’s discussion of the cat’s genitalia represents an important moment for her, since it allows her to confront sexuality openly and with a male for the first time. Without female friends to discuss her innermost secrets, Anne learns about herself the only way she can, through introspection and through interactions with her limited environment.