San shi er li means 'at thirty, one stands firm'. It comes from the Analects, where Confucius sketches his life by decade and says that he stood on his own at thirty. In modern Chinese it became the standard expectation that by thirty a person has a career, a family and a settled place in the world. The title Nothing But Thirty (三十而已, 'only thirty') plays on it, turning the pressure into a question.
