With a sense of smell more highly attuned than humans', they could bolt in panic before the thunder ripped, foretell an earthquake, flee from an advancing but still unseen predator. It made them seem prescient as wizards. A prey species, horses panic by design. They don't wait around to analyze the threat. In touch with invisible demons, they must have seemed to our ancestors four-legged emissaries of the ghost world.
Humans are prone to feel unworthy, even in the eyes of animals they control.
Sometimes votive horse heads decorated homes, for good luck, and religious dancers in Europe and Asia pretended to ride horse-headed sticks. Holding the horse god erect between their legs, shamans said they took flight and galloped across the sky until they reached heaven. When a warrior died, a horse in the funeral procession carried his ghost. His boots were arranged backward in the stirrups because ghosts supposedly had backward-facing feet. Throughout antiquity, horses carried the dead to the netherworld, as they do symbolically in state funerals today.