I certainly didn’t fit the classic profile of the aging stroke victim. At the time of my brain explosion, I was 38. I’d run eight half-marathons and had a diet and exercise regimen that helped me cross those finish lines. But I also had an intense job that involved booking groups—including NBA teams—into hotels in San Francisco. That’s what I was doing at 2 a.m. on the Friday before Christmas in 2013, welcoming the Los Angeles Lakers to their hotel. I got four hours of sleep that night, then drove 90 miles to my mother’s house to drop off holiday...