The Horse in Motion (1978), by Muybridge at Wikipedia
Many, many years later, I read a prose-poem by Franz Kafka called "The Wish to Be Like a Red Indian" which in its remarkable entirety reads: " If one were only an Indian, instantly alert, and on a racing horse, leaning against the wind, kept on quivering jerkily over the quivering ground, until one shed one's spurs, for there needed no spurs, threw away the reins, for there needed no reins, and hardly saw that the land before one was smoothly shorn heath when horse's neck and head would be already gone."
Kafka by Warhol (1980), by Artnet Magazine Online
But the sharpest memories I have of horses during my childhood and adolescence resulted from a summer vacation in Yellowstone Park when I was 13, traveling from one campsite to another on horses we rode down from a ranch in Montana. My horse was named Cheyenne and he developed a riding sore after a few weeks, and I was provided another steed whose name I don't even remember. Later when I saw the movie Brokeback Mountain, I was overwhelmed by the characters played by Ledger and Gyllenhaal, the beauty of the Montana country, and the remembered innocence of us fifteen boys from San Antonio who drove from Texas to Yellowstone Park accompanied by three coaches from a military junior-high school in San Antonio and an aged black man who was the cook of our "chuck wagon." I put those words in quotation marks because I simply cannot remember if the chuck wagon was real or a truck made to look like a chuck wagon. But regardless, both the old black man and the chuck wagon have vanished from my memory like Kafka's "horse's neck and head."
(Nonetheless, part of the horse's neck came back to me when I discovered many years later than black men were frequently chuck-wagon cooks in the wild west of the United States in the interregnum between the Civil War and the First World War.)
I also remember that our horses that summer in Yellowstone looked a lot more like wild ones than tame:
Wild Horses (2011), by anakin_it at Flickr Commons
To end this rumination, think on two facts I discovered reading books (and accept them as truth or don't); I accept the facts' validity without drawing a pro-human deduction from them: (1) Horses will avoid stepping on a human so avidly that this proclivity has been considered proof of their love and respect for human beings; and (2) In the heat of mounted battle, and particularly during the hand-to-hand battles of the Middle Ages, the horses of one side were known to attack the horses of the opposed side with their teeth and hooves.