It was a beautiful day, and Mary had just gotten home with her new horse, so she decided to go for a ride. She had spent several days, before purchasing the horse, riding and getting to know him and felt confident of his stability. When Mary went to saddle him, he reared back on his halter rope, broke loose and ran away. Mary was startled and surprised. Even though she had never saddled a horse on her own, she had seen it done many times at the riding stable.
Mary tried to saddle her horse from the wrong side. Most horses are trained for the left, and Mary had gone to the right side. Horses are binocular, meaning they see independently with each eye. If they are not trained to accept things from both sides, they can easily become frightened when approached with something that the eye may see as new.