An oft-cited maxim in higher education is that "faculty teach the way they were taught" because they receive little formal training in teaching before entering the classroom. However, little is known about the origins of faculty knowledge about teaching or the role their prior experiences play in the development of their teaching practices. In this exploratory study, we interviewed and observed 53 science, technology, engineering, and mathematics faculty at three research institutions. Using qualitative analysis methods (i.e., thematic and causal network analysis), we find that faculty do not only model their teaching after previous instructors, but also draw upon a varied repertoire of knowledge and prior experiences. These include knowledge derived from their experiences as instructors (46 respondents), their experiences as students (22 respondents), their experiences as researchers (9 respondents), and from their non-academic roles (10 respondents). In-depth analyses of two faculty members elaborate on the relationship between these varied types of prior experiences and how they interact with other factors including beliefs about teaching, instructional goals, and features of the organizational context to ultimately shape their classroom practice. The results suggest that instead of assuming that faculty lack any knowledge about teaching and learning, professional developers and policymakers should instead acknowledge and build upon their preexisting "craft" knowledge as professional teachers. Future research should focus on relationships between specific types of knowledge and teaching practice and how these varied experiences influence identity formation.