So while simultaneously listening to the Indianapolis 500 auto race in May 1967, I set out to calculate the genome equivalents of DNA per cell as a function of growth rate in log-phase cultures. It was great fun for someone with modest ability in math, and if you glance at the equations shown in Cooper and Helmstetter (1968), the derivations might seem fairly simple, but it wasn’t easy for me. As I thought about the preliminary equations that do not appear in the paper, I found the need to simultaneously envision expressions for the three distinct DNA replication intervals present in the more complex division cycles. Exasperatingly, one or two kept slipping away until at last I was able to retain all three at once, saw the formula, and quickly wrote it down. From there on, and in concert with Steve and Olga Pierucci, the equations flowed out and it was done.