On Monday, when I was seventeen, I wrote my confession letter and tore up half of it; when I was thirty-eight, I married someone else, gave birth to a child, and hid the name in an old cardboard box. During his third year in high school, he sat at the table behind Su Nanxi, watching her turn pens, hand out water, and see her back in the third row of graduation photos, but he never dared to say anything. Later they made do with each other and accepted their fate. This is a letter that has never been sent, and it is also a person that ordinary people think about repeatedly for most of their lives and cannot be together with. If there were any regrets in youth, it would probably be called Nancy.