Bill was almost 49 years old, and I had just turned 27. He was a full professor in the department of Molecular, Cellular and Developmental Biology at the University of Colorado, after doing a sabbatical year there in 1975-76, he had been recruited from CalTech in ~ 1977 to be the departmental chair. Although he had been trained as a biochemist, as he liked to say, "in Arthur Kornberg's" Department of Biochemistry, he was regarded by many as a geneticist. In fact, when he was the youngest person ever elected to the United States National Academy of Sciences in 1972, he was elected to the Genetics Section of the NAS. By the time I joined his lab his grant reviewers at the NIH described his early work on the morphogenesis of bacteriophage T4 as 'classic in genetics textbooks.'
That suited me just fine, because I was eager to learn how to use the tools of developmental genetics (although I too was formally trained as a biochemist at the University of Toronto--I, and most of my peers, considered myself a molecular biologist--pejoratively labeled "a cloner").