Students from the English as a Foreign Language (EFL) Program targeted in the present study are expected to achieve a C1 level of English proficiency according to the Common European Framework (CEF). However, only a five per cent of the students has evidenced this level on the institutional English exam (Ileusco Test, henceforth IT) for the past five years. Through the present descriptive-exploratory qualitative study we have attempted to inquire about the personal and academic factors that may have contributed to the successful development of the L2 competence of those learners. We used a questionnaire, individual interviews and focus-group interviews to ask 12 students about learning strategies, experiences and actions they have implemented to develop their l2 competence. We concluded that it is mainly students' commitment and self-discipline that helped them keep their L2 learning process successfully running; that despite the high quality of a school curriculum, a language program or a teaching methodology, it is students' autonomous learning initiatives that mainly enhance their L2 proficiency; and that L2 instruction in higher education seems to convey a stronger impact than elementary and secondary education.