As a "professional show mom", new rider, I think it is invaluable to have Trainers and Clinicians that have a true understanding of the horse. One that tells you that your assessment of what happens with your horse may be faulty. Sometimes we get trapped in all the "knowing our horses" and the "partnership," that we read the signals way wrong.
You may know your horse, and think you know its motivations, but someone with broader experience of horses in general may be able to point out the flaws in your reasoning. Maybe your horse seems angry to you, but is in fact just showing off a bit. Or maybe you should be more stern, instead of backing off because you have read the signals wrong. Each horse is an individual, and yes, you know your horse better than anyone, but sometimes that relationship can become one of enabling. The horse is allowed to not be able to handle something, because that is just "how he is."
There is a difference between knowing ones limitations and quitting, and sometimes it takes a professional to point out the difference.
More thoughts on this to come......