This chapter shows how boys and young men learned about manhood in affective transindividual processes and how they were recruited into shared tendencies in response to certain social situations. I argue that gender-specific sentiments were learned through mimesis or imitation, which included emotional contagion within assemblages of masculinity. Among the research participants in South Africa, events that mental health professionals commonly associated with post-traumatic stress were part of the intergenerational transmission of manhood. At the margins of urban Cape Town, violence and trauma were part of formal and informal rituals and rites of passage that turned boys into men. Biographical interviews show how physical and emotional pain became a prerequisite for the development of resilience among men. The reframing of injury and distress as markers of masculinity and manhood was tied to rigid gender norms that were nevertheless changing. Furthermore, although South Africa’s history of colonialism and apartheid did inform past trauma, the past never fully determined young men’s behavior. Rather than one primal trauma, multiple vectors activated memory according to relationships and interactions in the present within a shifting environment coined by ongoing social exclusion.