Every time you ride (or handle a horse on the ground for that matter), the two of you are teaching each other in your interaction - and, if you don't pay attention, sometimes the things that are learned aren't the things you want.
And I wasn't getting the job done - my job. Every time I rode him through the scary corner without giving him direction - where he made the decision to shy away, bend towards the outside and have his anxiety level rise - this confirmed for him that there was something to worry about. As far as he was concerned, I had hung up on him. And every time we finished a ride and left this issue hanging, that baked it in further. And it wasn't about desensitization - for some horses just hanging around there would have been enough - for Red it was about doubt in my leadership. He's a very smart horse, and he didn't trust any human to be in charge of anything and was worried about everything when I got him. He's learned that he can trust me, but it's a process that's ongoing, and I have to be aware of situations where the worry shows up and he's telling me that he needs extra direction and guidance for him to trust my decisions.
You have to be willing to get through the thing that's an issue, and get to the other side - if you don't, the issue won't be fixed. If your horse repeats the same behavior every ride, look hard at your contribution to this - in terms of your body position and any braces/blocks you may be adding in and your focus and direction/leading of the horse.
It's about getting mental and emotional buy-in from the horse, not making the horse comply. It's about the horse changing his mind, not because he's exhausted and gives up, or because he's punished, or because he just has no other choice. It's about the horse deciding that because you're not worried, he doesn't have to be either - it's about the horse letting go of the worry and giving a big sigh of relief.
My "wake-up" about not riding mechanically has really made a difference - when I rode Red last week, I decided that we needed to address what I was doing wrong that reinforced his opinions about the scary corner, and I did. I figured out some ways to help him through it - by giving him leadership and direction every step of the way. I knew it was important to finish what we started to resolve the issue - and it didn't mean working with him for an usually long time and he never got all sweaty - it was about finishing the job we started and getting him to a better place before we stopped. And he's not worried about it any more . . . funny how that works . . . I knew all of this already, but it sure was a good reminder!