This paper stems from research in Australia examining pre-service teacher and mentor teacher experiences on the practicum. The paper focuses on findings from the research, highlighting the tendency among the pre-service teachers to either valorise or demonise their mentor teachers, reflective of what we describe, following Kristeva and Britzman, as their powerful need to believe. The paper draws on psychoanalytic theory in order gain insights into this process, viewing the pre-service teachers' accounts of their mentors as fantasies that serve a stabilising function in order to manage the intense emotional demands of schools and classrooms. The paper concludes with considerations of how teacher educators might ameliorate the ideality of novice teachers, reflecting the insistence of the imaginary, and hence enable them to benefit more from the practicum experience. We briefly suggest the use of tools that work within the symbolic register to exercise a mediating role in the context of these intense demands.