As adults face the fierce competition and cruelty of society, more and more people like to “act young” and act with childishness, eager to return to the world of children. But if this mentality develops to the extreme, they will indulge in their own fantasies and refuse to grow up. This extreme form of psychology is called “Peter Pan syndrome” and is characterized as a mental illness. After several years of failed efforts, Marcella, 27, decided to divorce her 30-year-old husband, Eduardo. Eduardo was a teacher at a private university, and the conflict between the couple arose soon after the marriage. Marcella felt that her husband was unambitious and obsequious, and she said angrily, “He’s all playful and unmotivated in his academic and work life.” Marcella was puzzled by many of her husband’s actions after the marriage. Eduardo liked to collect toys such as electric trains and remote control cars, reasoning that he would let the children play with them when they grew up, when in fact Eduardo enjoyed playing with these toys more than the children. Eduardo’s hobbies are more than that, he spends most of his free time playing video games, and every time he leaves for work he hides the game console in a place where the kids can’t find it, reasoning that “the kids will break it. Eduardo was a “Peter Pan” and Marcella ordered her husband to see a doctor. After examination, the doctor only found that Eduardo was somewhat obese, and that was because he often sat in front of the TV eating fried food, cold drinks and various snacks, and in addition could not find the root cause of his eccentricities. Marcella despaired of her husband’s childish temperament and turned to a psychiatrist. The psychiatrist told her that Eduardo’s symptoms were unmistakably “Peter Pan Syndrome”. People suffering from “Peter Pan syndrome” have entered adulthood in terms of physical age, but they are not psychologically compatible with it. They talk and act like children, always avoiding responsibility, life and love, and generally live with their parents at an early age, not thinking about long-term things. The “Peter Pan Syndrome” has to mention the overgrown Peter Pan, who was born in 1904 under the pen of Scottish writer James Barry, and later became a household name in fairy tales, and his story has been put on the screen many times. Peter Pan lives in a dreamlike “Neverland” and never wants to grow up, but after all, this can only appear in fairy tales and cannot be accepted by reality. “Peter Pan syndrome” patient is the real Peter Pan. In 1966, psychiatrist Eric Berne first introduced the concept of a group with psychological maturity difficulties, and in 1983, American psychologist Dan Keeley also wrote an article describing this group: “This group aspires to play the role of a child forever rather than become a parent.” These Peter Pans are fun-loving and easy-going, but inevitably have many of the weaknesses of children, such as indecisiveness, lack of self-protection, and the desire to be accepted and fear of rejection. Therefore, their behavior is very disproportionate to their age, which in most cases is harmless, but one day, when they suddenly understand that life is not as satisfactory as they thought, it is already too late.