Before I started running marathons , I preferred the flattest and easiest possible race courses. Give me a pristine, pancake-flat, beachfront race, and I was good to go. Hills had always been a weakness of mine, and I thrived running on the track . My first marathon was on the coast of South Carolina, and while it was as flat as can be, it also got a little boring after a few hours. Still, I struggled so much in the final miles from fatigue that I could not fathom adding hills into the mix. It wasn’t until a year—and three marathons later—that I would consider all-out racing a hilly marathon. A week after fun-running the 2023 New York City Marathon , I sat down at my computer to research my next race. Suddenly, my phone rang. It was my Uncle Greg calling from his home in Berkeley, California. When he learned what I was doing at the moment, he offered a suggestion: my next marathon should be the San Francisco Marathon the following July.…