On the second floor of our house, there used to be a resident who lived there for many years, until recently they moved out. It can be said that they are the neighbors of my family for the longest time. Although they have moved away, I often think about when they were there. Although under the influence of modern urban civilization, even the neighbors who have been with each other for the longest time are just “gentlemen’s friends” who smile and nod when they meet, but every time I go up and down the stairs, I can always open the door of their house through the door. A glimpse…