My horse once refused absolutely point blank to set foot on a particular path, to the point of rearing straight up on the air and shooting off backwards, squealing like a banshee.
My friend’s horse had no such compunctions, and set off merrily along said path, while mine continued kangarooing up and down on the spot shrieking.
About fifty yards along, the path collapsed and sent my friend and her horse about fifty feet down a ravine.
Neither of them were hurt – apart from an impressive collection of bruises, but I still wonder how my horse knew that the path wasn’t safe before he had even put a single toe on it. Maybe he was just brighter than me.