The present study investigates how the L2 learning experience shapes multilinguals' motivation to improve their writing skills in Spanish, a language they study at university level. Within the Second Language Motivational Self System Theory (L2MSS), the L2 learning experience is often neglected when it comes to interpreting and discussing findings on motivation. We propose that the analysis of the L2 learning experience should acknowledge both formal and informal settings, such as the family context, in order to research why and how a person chooses to develop certain linguistic abilities like writing. Given that the L2 learner experience is spatially and temporally bound, the concept of sensitivity to initial conditions, i.e., the conditions or changes that may trigger the learner to move towards enhanced language learning, will be adopted to research the L2 learning experience. The aim of the study is twofold. First, to investigate the Spanish learning experience as a function of the initial conditions referred to by the participants. Second, to research how the Spanish ideal and ought-to selves are related to the students’ motivation to use and learn or maintain Spanish skills. The data consist of a questionnaire answered by multilingual university students of Spanish (n=21) and written autobiographical narratives. The participants belong to two groups: one group of Spanish heritage language learners (n=10) and one group of native-Swedish speaking L3 Spanish learners (n=11). Overall, family reasons, previous school experiences, high proficiency in Spanish, previously acquired languages, contact with the linguistic communities, language use and context are all aspects tightly connected to the students’ motivation to learn, maintain and develop Spanish language proficiency. The L2 learning experience, as a wider construct dependent on the sensitivity to initial conditions, must be considered to understand the complex nature of multilingual literacy development.