Through the Peer Writing Tutor Alumni Research Project (PWTARP), the authors have set out to explore and document what peer tutors take with them from their training and experience. The Peer Writing Tutor Alumni Research Project has made it possible for the authors to sample and analyze more systematically the reflections of 126 former tutors from three institutions, Marquette University, the University of Maine, and the University of Wisconsin-Madison. In this article the authors theorize peer tutoring as a form of liberal education for peer tutors themselves. And they support this claim with empirical evidence that this is deep learning that endures years, even decades, after graduation. They open by defining liberal education, using Kenneth Bruffee's arguments about peer tutoring and liberal education and William Cronon's definition of the goals of a liberal education. They then describe their survey methods and research participants. In the heart of the article, the authors develop and illustrate each of their major findings, demonstrating the breadth and depth of what former tutors have taken with them. In their conclusion, the authors argue that this research has profound implications for writing centers themselves: systematic tutor alumni research allows writing centers to resituate themselves as central to the educational mission of their colleges and universities. (Contains 2 figures and 2 notes.)