In my early thirties an epiphany emerged from my training log that shaped the arc of my life. I was competing in age group triathlons at the time and as a natural record keeper I carefully logged every workout, every race, and every personal best. One day while flipping through the pages of my logbook, a startling revelation jumped out at me. On any given day I might have more energy or less energy, faster lap times or slower lap times, better splits or worse splits, than the