This content analysis examined 1,710 statements made in post-lesson reflections of elementary education preservice teachers (N=120) after their first and second unassisted lessons during an early practicum experience that accompanied a mathematics methods course. The activities constituted authentic learning experiences in which preservice teachers planned and executed two appropriate mathematics lessons featuring hands-on materials and open-ended problem solving for elementary students. Predominant reflection themes focused on elementary student motivation, student learning, improvement of lessons, student skill levels, student behaviors and feelings. The authentic learning format allowed preservice teachers to develop professionally, taking responsibility for their own learning with the support of their mathematics methods instructor, host teacher, and peers. Reflections showed that preservice teachers had become aware of the complexity of teaching, analyzing problems from many viewpoints.