Although parent–child separation and environmental pressure cast numerous challenges to left-behind children, some of them still achieved positive development. This study employed a life-course perspective to reveal the dynamic developmental trajectories and concealed protective factors among college students with left-behind experience. A qualitative approach with in-depth, semi-structured interviews were conducted to collect six participants’ life histories. Each participant’s life trajectories were delineated. Their life stories were coded thematically. The analyses of life trajectories present the uniqueness of each person’s life trajectory as well as common demands at each development stage. Two internal assets (empathy and initiative) and three external resources (positive educational expectations from family, active attention and acknowledgement from school and low social pressure from the community) were identified as significant protective factors during the left-behind period. This information provides important insights that can be used to create early interventions in building resilience against development problems among left-behind children.