This paper focuses on learning that takes place outside formal classrooms within groups or teams. Based on the conceptual framework of informal learning, adult learning and lifelong learning, it investigates how two contrasting groups of adult learners in Vietnam, Mekong doctors and Hanoi hairdressers, learn, interact, and collaborate through their informal learning experiences in the workplace. These are two 'co-present groups' or two 'complex systems'. For Vietnamese learners, the challenges of Confucian heritage culture, or the lack of awareness of cultural differences, created obstacles to collaboration and participation. The contribution to this Special Issue argues that co-present group learning applies well to non-Western Confucius-based cultures and other countries with similar values, despite this lack of awareness of cultural differences.