Engineering students move through a wide array of experiences on their path to becoming an engineer. Based on semi-structured interviews of 121 engineering students, our qualitative analysis illuminates what students are communicating as important features of their learning of engineering design. We describe these accounts in terms of sources of learning, what lessons were learned, and how the learning occurs and is applied. Formal education in engineering (classes) featured prominently in student accounts of learning design, but students also credited non-engineering classes and many other kinds of learning experiences. This work suggests the educational value of reflecting on and communicating about learning experiences in engineering, and how educators might facilitate these activities.