An elegant woman in her 40s is addressing 200 young men and women in a large auditorium in Shenzhen, the sprawling city just across the border from Hong Kong. “Is it necessary to fall when learning to walk?” Sun Yu asks. “Necessary,” many of her audience of workers at a Fuji Xerox factory loudly respond.

Ms Sun launches into a rambling tale about a young Englishman who works in a factory but loses his job just when his father falls ill and needs financial support. Things start looking up, however, when on a visit to the British Museum the young man sees a photo of an old ship that has weathered many storms. Fast-forward a couple of decades and he is the head of an insurance company. The storyline might be convoluted but the moral is clear: “Life,” Ms Sun intones, “is a university with setbacks.”

Ms Sun is not a celebrity motivational speaker, nor has her audience paid large sums to listen to her. She is one of a growing band of psychiatrists and psychotherapists who work with big factories in southern China to help their young migrant workforce cope with the stresses of work – and growing up.