I. Robert Lehman, PhD is the William M. Hume Professor, Emeritus, in the Stanford School of Medicine. His research work in biochemistry has yielded important contributions to the understanding of DNA replication, recombination, and repair, including foundational work on the enzymes DNA polymerase and DNA ligase. Lehman describes early formative experiences, including service in World War II, university studies, and his connection to the Department of Microbiology at the University of Washington in St. Louis, which was a dynamic center for DNA research and discovery in the 1950s. As part of Arthur Kornberg’s team, he came to Stanford in 1959 as an assistant professor in the then new Department of Biochemistry. He describes the department’s collaborative research culture, teaching curriculum, and administration. Lehman explains his work on DNA enzymes, in teams that included then and future Nobel laureates, and how contemporary technologies are now building on earlier discoveries. He reflects on the increasing complexity of biochemistry as well as on growth and change at the Stanford School of Medicine.