"I agree 100%, except..." LOL.
I think many horses aren't very demonstrative or cuddly, but are very attached to their person, their routine, the things they know.
I probably will be called insensitive or told I've never had a real relationship with a horse (I have, though). But I don't think the relationship between horse and rider is ever at all mystical, mystical being inexplicable, supernatural. I think though, that it sure can LOOK like that to someone observing. My friend is constantly amazed by how my horses interact with me, and I try to explain it, but it's hard to explain.
I try to tell him, it's like a rather fast paced conversation that goes on constantly. The horse is constantly telling you things, and you telling him. Horses have body language. The angle of their hind quarters to you, the way they move their head, neck, ears. And you know things they more sense or feel. For example, if I keep my pony in the barn, my old horses is going to be more sensitive, and more nervous, the entire day. A correction he would barely listen to otherwise, he would practically be hysterical over on one of those days. To me it's so obvious that he's having a bad day, he says it in every single step and motion of his body.
That could be what she means by 'mystical', but to me, it's as plain and simple as two people talking to each other and telling each other everything. To me it's so obvious what the horse is 'saying'. I think that just comes with experience, work and time - and the more experienced people I feel are better at it than me, as if we're all standing on a ladder, and some people have climbed further up.
I think it's made up of very simple do-able building blocks - made up of training and activity and time and work on both the part of the horse and rider. Not hanging around staring at each other, but riding, working, that I think is what makes the relationship to the horse the deepest. I feel completely different about horses I'm not working, or haven't worked. I think that the relationship is more intense, more close, with a horse one has worked with and tried to accomplish something.
Some people just never get very good at working with animals. I think they have principles, ideas, emotions that hold them back. So they don't open up to what is happening between...maybe that's what she means by mystical, LOL! But to me, it's more like learning and making the effort.
I had one friend who could never, ever time anything right around the horse. The pony would start to paw, the guy would be - I don't know what he was doing, looking at something else, I guess. The pony would paw for some time and I'd say, 'don't let him do that, say no and jerk the lead shank', and he'd be jerking away at the lead shank STARTING AFTER the pony had already stopped pawing!! He was getting punished for standing there doing nothing!!! I just COULD...NOT...get it in this guy's head, this simple principle of correction and reward. See, react to the wrong behavior, reward the right behavior. His timing was completely off.
I later found out he was drunk most of the time. So I DO think timing is within the ken of most sober people!!!!!
But the thing is, the pony just did not react to this guy, he could yank on that pony all he wanted, as hard as a big man can, the pony would do NOTHING for him. SOMEHOW...that pony seemed to know that the guy was not going to be a reliable leader. Because what the guy is telling him to do, is so disconnected and is not timed properly. I think that is also very non-mystical. A herd leader proves himself to be a herd leader by his actions. Same thing, I ride a horse, turn him over to my sister, and no matter what she does up there, the horse does exactly what he wants. The horse knows the person can't 'back up what they say'. They KNOW when a person is not effective.
That is really what training is about, that type of timing. Correct the undesirable behavior right when it is happening, get it to stop. Reward the right behavior.
Mystical...? It's as if you compare the 'water cooler friendship' of someone you constantly have breakfast or lunch with at work, and talk about the weather, vs your spouse, having children together, nursing them through sickness, weathering financial storms, working things out when things go wrong. Working together creates that relationship. The horse knows it, so does the person, I think it's the same from the horse's point of view.
I think some horses get a bad start with poor training, or have a suspicious, untrusting temperament from birth, or the most common - are simply 'spoiled' (have gotten in the habit of not obeying unless absolutely forced to with escalating punishments). Skilled trainers seem to get them to be much more reliable, but they may 'regress' if with an unskilled ('weak') person.