With the call for reformed teaching practices in STEM education, there is a need to spread effective teaching practices to classrooms. Affective drivers can lead an instructor to improve their teaching practices, but they are infrequently addressed or recognized. This case study followed one instructor through her General Chemistry course over a summer and fall semester to gain a detailed understanding of the affective drivers that impacted her teaching practices. Semi-structured interviews, based on classroom observations and field notes, revealed that the instructor had self- and student-focused factors that influenced her affective drivers. The self-focused factors included feeling basic emotional needs, feeling intrinsically motivated towards self-improvement, and feeling self-efficacy regarding instruction and chemistry. The student-focused factors included feeling like a supportive faculty to students, feeling empathy towards students, and having expectations for students' personal successes. Considering the difficulty of long-term change in faculty, the affective drivers are rich sources of motivation. Understanding these affective drivers, particularly if they are common to other instructors, could allow for targeted instructor self-reflection and guidance. The authors suggest that approaching self-reflection through an affective lens will allow for more effective support to change and adopt effective teaching practices.