You know I have never seen a horse run a barrel pattern without a rider on its back. I never have. How do those riders get the horse to run the pattern? Is it because the rider is controlling the horse's feet? How do they turn around the barrel? Is it because the rider rates the turn and applies an aid to the body of the horse? Do they not have control of the horse's body?...
No, they do NOT control the body. Horses have been bred for thousands of years to be willing and submissive. And we teach them in part by controlling their alternatives - making it unpleasant to refuse us, and easier to obey, until they form a habit of obeying.
The problem is the word "control". Can you direct a horse to do something? Of course! And they usually will do it, particularly if they are in the habit of obeying. But you do not CONTROL squat. Run your horse into some Teddy Bear Cholla and see how much control you have!
If Mia is genuinely afraid of something ahead of us, I can whip her rump with a leather strap, and she will still go in reverse. As the lady I took lessons from put it, "You cannot make a horse do anything. You can only make all the alternatives less desirable." And if something in front says "FEAR ME!!!!", then the leather strap on Mia's butt gets ignored.
With time, she is less likely to be overwhelmed with fear, because she gets used to my telling her to go from A to B being safe. But that isn't something I can teach her in an arena. And that is the point for this thread:
You cannot teach a horse in an arena that it will be safe outside the arena.
At some point, you have to leave the confines of the arena and go out and start facing those fears. And what will they fear? Depends on the horse. Some are born pretty level headed. Others, like Mia, have a lot of deep seated fears. And in an arena, she never needs to face those fears. The walls of the arena protect her - or so she believes. We could spend 20 years riding in an arena, and she would be no better prepared for the real world. She cannot face her fears until she is exposed to them.
And just as only about 50% of groundwork carries over to when my butt is in the saddle, only about 50% of what she learns in the arena carries over to outside. So at some point you have to take the horse out and let it learn about the world. 100% good in the arena is about 50% good on the trail, IMHO. That is because the horse's mind controls its body. And the horse can't learn to trust me in a scary situation until we've FACED scary situations together, me on her back. If that puts me in danger...well, I can accept the risk, or stay in the arena forever.
BTW - Cowboy is our BLM mustang pony. He is great on a trail. Ride him in an arena, and THAT is where he gets scared! So much depends on the horse!