This article reports the results of a qualitative case study investigating the self-authorship characteristics of learners in the context of an interdisciplinary curriculum. The study identifies the students' assumptions about knowledge, self, and relationships. The findings are based on evidence from reflective essays written by students upon completion of their undergraduate courses. The findings suggest that graduates in this program have come to see interdisciplinarity as a way of both thinking and living, and have additionally developed a sense of agency over their education and future careers. In their view, engaging with broader horizons and seeing multiple perspectives are the most valuable skills acquired through their interdisciplinary education. Above all, the students perceive the responsibility they have had for their own study program as contributing to their development as self-directed learners.