Why didn't he let people know who he was?
Unknown refers to people who often appear in novels without leaving their names or identities because they may be the creators, authors, or other related parties of a character but may not necessarily have a real identity. In some novels, anonymous names may be used to create a mysterious and unpredictable atmosphere because their existence is not clearly known or recorded. They might be authors or editors of a novel, comic, game, or movie, or just ordinary netizens. Others may choose not to reveal their true identity because they don't want to establish contact with others or because they don't think their identity is important. Therefore, although anonymous names often appear in novels, they don't have to let people know who they are. It depends on their choices and the plot of the novel.