A case of multilingualism is presented and analyzed in order to establish a parallel between multilingualism with multiculturalism and the “Casanova” syndrome. The concept of “imagined proficiency” is employed in order to describe the gap between the self-assessment of language skills in the different languages and their external assessment. The psychological correlates of an “extreme” case of multilingualism with multiculturalism are analyzed and explained on the basis of Winnicott’s concept of transitional space.