The purpose of this study was to explore the complex cognitive and affective challenges of teacher candidates in their development toward self-efficacy in their teaching. Twenty-two teacher candidates recorded their challenges and thinking process during the last six weeks of their practicum. Following their placement, they completed a summative reflection, in which they noted changes in themselves and described when or if they felt confident as classroom teachers. Four themes emerge as the challenge or condition for their self-efficacy: effective classroom management, successful curriculum planning and implementation, positive rapport with students, and supervising teacher approval. This research suggests that teacher preparation program educators can support teacher candidates' self-efficacy by understanding the developmental stages of teachers, supporting critical reflection, and using motivational and descriptive feedback to improve practical skills.