Graffiti Experts in the Office Building

Uncle Chen, an elderly cleaner, goes to work on time every day and says that "living is my job." He always carefully wipes an abandoned office building late at night. Everyone was puzzled. It wasn't until he fell ill and was hospitalized that they discovered that it was the former site of his company before bankruptcy. What he wiped was not the dust, but the graffiti on the wall from his daughter's childhood - she had died in the accident that bankrupted him. It turns out that his real "job" for thirty years was to stay close to her.