On a Sunday, I had the best riding day yet. Out on the Gymkhana field, I played horse tag. The horses flew across the sand, their riders leaning in awkward positions to evade whoever was it. We clumped up into groups and laughed, then suddenly scattered, like that school of silvery fish from Finding Nemo. And as I watched while resting, the streaks of white and mahogany and light brown were etched on my eyes in the warm, lazy, Sunday sun.