Intrinsic motivation is considered the dominant factor in the motivation of adult students in continuing postgraduate education. However, the strength of an intrinsic motivation to learn does not explain the phenomenon of dropout where the student withdraws and does not return or where the student withdraws and then recommences their postgraduate research studies. This paper draws on qualitative data collected as part of a doctoral thesis to examine this phenomenon ethnographically. The study explores motivations which have declined or disappeared under the influence of external factors and the effect that these external factors have on the motivation to learn with respect to their influence on student withdrawal.