Horse training is an art. But it also has rules that govern how to work with and train a horse.
For instance, when you're training a horse to do something, you don't want to drill him with it so much that he becomes sour on it and unwilling to do it next time. The trick is to get him doing what you ask, then asking him to do it a few more times, then stop asking.
You can ask him to do it more for you next day but you should stop asking for too much.
Here's a human view on why that's important.
If you were to get a piece of paper and write word "training" on it, chances are you would do it just fine.
But what if I asked you write it again? Why would I ask you to do that? Because I just want to make sure you know to do it. So, I ask you to write it again.
When you get done writing it again I pat you on back and say "Way to go. Now, let's do it again."
Apprehensive and sighing, you do it again. This time, after you write it, I ask you to immediately re-do it because I want it capitalized.
You give me a dirty look and rewrite it.
Then I ask you to do it again.
Now....aren't you getting tired of rewriting word "training"? After all, you did what I asked. Plus, I asked you to rewrite it and capitalize it. It was still same word and you were still doing what I asked but I just wanted to make sure you were doing it.
This gives you a feel for why a horse shouldn't have to redo something over and over. The rule is once he gets it and does it a few more times then quit asking for it. Give him something else to do. Make it interesting for him.