Writing a diary was a way to record life and feelings. It could help one reflect on the past and plan for the future. A diary could contain many things, such as personal experiences, thoughts, feelings, and so on. Some novels would describe the protagonist's life experiences, thoughts, feelings, and so on in the form of a diary to show the protagonist's inner world. Writing a diary could also record some opinions and thoughts about things, such as comments on a person or an event, etc. Some novels would also show the protagonist's inner thoughts by writing a diary so that the readers could better understand the protagonist's personality and emotions. A diary could be used to write many things, to record the bits and pieces of life, and to record one's views and thoughts on things. Different novels would use different ways to write a diary, hoping to show the inner world and emotions of the characters in this way.