This research focuses on the identity development of ten student teachers during a one-year Teacher's Pedagogical Studies program in Finland. The students wrote narratives that represented their beliefs of 'good' teaching, and in this study, these beliefs are called as personal practical theories (PPTs). After two teaching practicum experiences, the students were interviewed about the realisation of their PPTs. The most significant change, based on both the narratives and the realised PPTs, was related to contextual factors (such as collaboration with school members and shared organisational culture) that became increasingly significant as teacher education proceeded, which may narrow the potential gap between the student teachers' ideals and the real world of the schools. On the basis of the results, we see that it is extremely important that future subject teachers should have the opportunity to focus on topics that fundamentally affect their forthcoming work, that is, their personal images, ideals, and values regarding teaching.