This study aimed to explore the critical reflection experiences of teachers who took part in effective and ineffective professional learning events. It examined the influence of D.A. Kolb's reflective observation stage within the experiential learning theory (ELT) framework on teachers' professional development. Using a qualitative interpretive phenomenological method, the research investigated teachers' viewpoints, beliefs, and experiences related to various professional development activities to evaluate their effectiveness. Eleven teachers attended the same educational conference. The investigation involved semi-structured individual interviews and a focus group discussion. The interview questions centered around the concepts of enactive mastery and vicarious experiences. Open-ended discussions allowed participants to explore their experiences of professional learning. To highlight emergent patterns, this study employed a phenomenological technique to analyze data and identified critical observations through an inductive coding method using the NVivo software. The study's findings suggested that the reflective process necessitated time, collaboration, and structure during professional learning sessions. Moreover, having a group of peers was advantageous for critical reflection. They created a learning environment where support was the norm, and dedicated time encouraged self-reflection, which promoted effective growth in teacher development. The researchers found that inquiry-based professional development promoted introspection and facilitated profound learning. The research emphasized that teachers responded positively when professional development facilitators allowed participants time to link their personal experiences to new teaching methods, prompting reflection and collaboration with peers.