Increasingly, elementary teachers are being asked to teach the missing elements of a STEM education--computing and engineering. Over the course of a year, we worked with an entire elementary school (K-6) to implement computing and engineering lessons. Through persistent observation, field notes, and interviews, teachers revealed both enablers and inhibitors to successful classroom implementation. These fell into two categories--externally provided and internally cultivated enablers and inhibitors. We provide evidence for these claims and discuss how internally cultivated enablers and inhibitors can lead to or impeded the successful implementation of computing and engineering lessons in elementary education.