Have fun alone, okay? All the music is good? During the Warring States Period, Mencius suggested to Qi Xuanwang that it was better to have fun alone than to have fun with others. It is suggested that Qi Xuanwang share music and happiness with the people, so that the people can be educated in music and the country can be stable. More than 2300 years have passed, and Mencius' ideal of "being happy but not happy" has finally come true. In recent years, many public green spaces and squares have been built in various cities, and most of the parks that used to charge fees are free to open, and ordinary people are also enjoying the happiness brought by free. However, uncivilized behaviors such as destroying square sculptures, trampling on grasslands and littering garbage peels can also be seen everywhere, which makes people feel sorry. This raises a question: is it good to have fun alone? All the music is good? Some people advocate "playing alone" because certain restrictions can reduce the damage of low-quality people to public facilities. Personally, I think it is better to have more fun. The essence of Mencius' thought that "solo music is not as good as public music" does not mean the sharing of music itself. Music is superficial, but the essence is: when sharing music with people, people will be enlightened and happy in music. In today's words, this is called: cultivating sentiment. I think the free and open urban green space, squares and parks have the same function as Mencius' music. However, squares and parks in cities are now open for free, but they also lack guidance and management. Uncivilized behaviors such as climbing sculptures have become activities that people line up to follow. In this way, the true intention of freedom and opening up is lost, that is, to make people happy physically and mentally and to be educated in play. "It is better to have fun with others than to have fun with yourself", but "having fun with others" lacks system and management, which is the indulgence of selfish desires and the decline of social moral consciousness. May we unite to safeguard our squares, green spaces and sculptures, and may we unite to safeguard the "happiness of all" of our people.