In the literature of learner characteristics in applied linguistics, learning attitudes, strategies and motivation have received most attention. These learner individual difference variables have usually been seen as background learner variables that modify and personalize the overall trajectory of the language acquisition processes (Dörnyei, 2009). Embedded within a mainly psycholinguistic perspective on L2 acquisition, previous research on these background learner variables tended to examine one variable independently of other variables, and of the learning contexts in which L2 learners are situated (Ellis, 2004). For example, early studies on good language learners focused largely on learning strategies. Consequently much less attention has been given to the interplay between various individual difference factors as well as interaction between learner individual and contextual factors. This case study set out to investigate how the contextualized learner learning attitudes, strategies, and motivation might differentiate successful and less successful ESL learners. Data were collected through interviews, diaries, and follow-up email correspondence with both successful and less successful second-year university ESL students. Analysis of the data suggests that learners’ psychological relation to the English language learning process depends in large measure upon the social, institutional, and interpersonal contexts “in which individuals find themselves, the purposes for their being there, and their personal biographies” (Duff & Uchida, 1997, p. 452). Learners’ investment in English language learning and different levels of success as ESL learners could thus be the outcome of dynamic interactions of different learner factors situated in the particular learning contexts. Implications of the results for how institutions and teachers may empower ESL students in their investment in learning the target language are discussed.