Does anyone believe in parallel time and space? Two selves in one time and space, although they are the same person, they live different lives and are at different ages. A diary records a period of youth. Some people will feel pale after reading it, while others will burst into tears after reading it. Thirty-year-old Chen Meng and seventeen-year-old Chen Meng, one person and two lives in parallel time and space, who will be whose savior?