Chou Wei-pao infers from his experience that there is a major new fad every two years in Shanghai, and minor fads (within a given category) come and go even quicker, burning out within three months.
周文保歸納，上海餐飲的流行大概每兩年一個大分類，而小分題的流行更快，幾乎都沒有三個月的好光景。