What is the theme of the lonely journey

The theme of the lonely journey usually involved human loneliness and the desire to explore the unknown world. This kind of theme often appears in science fiction, fantasy, and adventure novels, where the protagonist usually embarks on a lonely journey to explore the unknown in search of answers. In their lonely journey, the protagonists may encounter various difficulties and challenges, but they persevere and eventually discover new knowledge and truths, and in the process, find their own position and meaning. Therefore, the theme of the journey of solitude also included the concept of self-exploration and the search for the meaning of life.