In this paper, Jo Boaler and Sarah Kate Selling describe a follow-up to the award winning research study Jo conducted of two schools in England. The paper describes what happened when Jo contacted the adults 8 years after they had left the schools, to find out about their mathematics knowledge use in life. The study shows that the young adults who experienced the two different mathematics teaching approaches developed profoundly different relationships with mathematics knowledge. Importantly, adults who had attended the project-based school, Phoenix Park, had moved into significantly more professional jobs, despite living in one of the lowest income areas of the country. This upward mobility appeared to derive from the active relationships with mathematics they had developed in school.