In this large-scale qualitative study, we use an emergent design to explore pre-service teachers' (PST) motivations to enter the profession. We open-code 2,798 PSTs responses to the directive, 'Explain why you decided to become a teacher', given over the course of a six-year period from one large Texas teacher preparation programme. Using constant comparative analysis, we identified three categories of motivation into the teaching profession: altruism, intrinsic motivation, and socialization influences. Each of these explain why PSTs were motivated--to, by, and from--entering the profession, respectively. However, descriptions of each category differed from findings in previous research, as our study addresses methodological, contextual, and conceptual gaps that have persisted throughout this field. Findings offer implications for increasing the teacher pipeline through targeted recruitment and increased informal teaching experiences.