I (the first author) conducted my doctoral research using the self-study methodology in the 2022–2023 school year to reflect on my teaching practices within the curriculum adaptation perspective. In this way, I aimed to question, understand, make sense of, and share with others my teaching experiences with the dilemma of adhering to the official curriculum and adapting it. I also involved two critical friends (CFs), one from outside and one from within my school, and conducted 22 semi-structured interviews with them regarding my teaching practices. This article focuses on the impact of the critical friendship relationship I established with my two colleagues on my professional growth. After my advisor (the second author) and I thoroughly analyzed the interviews’ content, we created eight themes: (1) clarifying my thoughts on curriculum adaptation, (2) defending my weekly course syllabus, (3) engaging in self-confrontational dialogues, (4) questioning my teaching identity, (5) opening my classroom privacy to criticism, (6) showcasing my teaching activities, (7) coping with my researcher identity, and (8) acting as a mirror for my CF2. This study significantly contributes to a better understanding of the essential value of critical friendship in self-study research.