The name of the young man is Chen Lang. He has just graduated from college at the age of 22. He has been having some strange dreams since he was ten years old. It is like he is in another world and is observing another self. At first, he doesn't care about these dreams, just thinking that his imagination is too rich, and this kind of dream is not done every day. At the beginning, he can have once a year. After each awakening, he will only have some dreams vaguely, but he forgets all the details. As he grows older, he enters this dream more and more frequently. In the end, his life in the dream gradually becomes vivid and coherent until he is twenty years old. Chen Lang's mind has inexplicably added many familiar and unfamiliar memories. After long and repeated contemplation, the answer he got is that he may have lived in the second life, but he doesn't know why his memories of his previous life awaken in this life.