It is assumed in teacher education that student teachers’ involvement in inquiry-based learning and teaching practices will lead to re-conceptualizations of what the discipline is and how it is and could be learned and taught. Nonetheless, the change of students’ subjective theory of teaching (Marland, 1995) is not so easy. The personality factors, e.g. openness to experience, entity vs. incremental perspective on humans abilities and personality, and students’ learning motivation (Pintrich, 2000) may foster, but also undermine it. The correlational study (N=158) investigates the relations of student teachers’ willingness to apply inquiry-based teaching in their own teaching to the extent of their experience of being taught in this way, to their scores on five-factor personality model, on incremental perspective on personality, and on their learning motivation. We also asked the 34 science students about their self-concept as a teacher to provide deeper insight into their ideas for future. The results show that previous experience with IBSE is the most important factor. But openness to experience and mastery orientation in student’s motivation turned out to be also significant factors. The findings support the notion that elaborated reflection of the inquiry process and of inquiring mind/person is crucial (Klein 2004).