Every year school districts must fill tens of thousands of teacher vacancies in mathematics and science. Reasons for the high rate of attrition are described in general terms, such as lack of administrative support and dissatisfaction. Analysis of direct quotes from qualitative research, however, suggests the presence of cognitive errors within the decision-making process of those teachers who quit. Cognitive errors include all or nothing thinking and fortune telling, among others. Results of this study are interpreted in comparison to the attrition literature. Suggestions for future research, such as Cognitive Behavioral Therapy training for preservice teachers, are presented.