南城已南青衫薄
[nán chéng yĭ nán qīng shān bó]
This is often used to describe people's loneliness after a breakup. Literally, it refers to standing in the South with light-clothed body. Metaphorically, the phrase conveys the meaning that time has passed, the scenery has changed, and people are also different as if saying goodbye to the past self.