Adult L2 acquisition has often been framed within research on the Critical Period Hypothesis, and the age factor is one of the most researched topics of SLA. However, several researchers suggest that while age is the most important factor for differences between child and adult SLA, variation in adult SLA is more dependent on social and psychological factors than on age of onset. The present qualitative study investigates the role of migratory experience, language use/social networks, language learning experience, identity and attitudes for high performance among Swedish L1 French L2 users in France. The study constitutes an in-depth thematic analysis of interviews with six high-performing individuals and four low-performing individuals. The main results show that the high performers differ from the low performers on all dimensions, except for attitudes towards the host community. High performers are above all characterized by self-reported language aptitude and an early interest in languages, which appears to have led to rich exposure to French. Also, they exhibit self-regulatory behaviors and attribute importance to being perceived as a native speaker of French—both for instrumental and existential reasons.