If medical educators are to perform at our best, it is vital that we understand how people learn. Learning, not teaching, is the ultimate outcome of medical education, and we are unlikely to foster it effectively if we do not understand what it is and how it takes place. Yet most medical educators have little or no background in formal educational theory. If we are good teachers, it is frequently because we were blessed with good educational instincts, or because we had the good fortune to study with and emulate other good teachers. We need not leave our capabilities as teachers entirely to chance, however. Those of us who are not particularly accomplished educators can learn a great deal from the educational literature, and even those who are already very good can hone our skills even further. Happily, thoughtful people have been studying learning for many years, and important insights are readily available, if only we are prepared to look beyond the boundaries of our own field.