* She needs an outlet: Anne is a teenager living in the midst of World War II, confined to a small attic in hiding. She's experiencing intense emotions, loneliness, frustration, and a longing for normalcy. Writing in her diary becomes her way of expressing these feelings and processing the difficult reality she's facing.
* She feels isolated: Being in hiding, she's cut off from her friends and normal life. Writing to her diary, whom she names "Kitty", gives her a sense of companionship and someone to confide in.
* She wants to preserve her story: Anne hopes that one day, her diary will be published. She believes her experiences are valuable and wants to share her story, not just for herself, but for future generations to understand the horrors of war and the resilience of the human spirit.
In short, Anne starts her diary out of a need for emotional release, a desire for companionship, and a hope to document and share her unique perspective on the world.