Using longitudinal data, this study examined the enrolment status of individual children left behind in the global trend towards 'quality education'. The study identified common characteristics among dropouts as well as the existence of children who managed to complete primary education but could not progress smoothly. Among them, some children's grade levels were lowered by more than two years when they transferred from public to private schools, and their grade levels increased by one or more years when they transferred from private to public schools. These surprising enrolment patterns provide evidence of an ignorance about systematic learning.