Knowing when to move on

Do you ever find yourself doing the same exercises with your horse? I do all the time and it kills my horse. Going off my leg is the biggest thing that I find myself paying more attention to. Going off the leg of course is very important and especially if you plan to ride someday with no strings attached. Think of it this way; first learning an algebra problem, then doing the same one constantly every day except with a little twist to it. I mean you get board of doing it no matter how your doing it your getting it done, and then your getting asked again over and over. With this case your horse is just so board of doing it the he/she becomes worse at doing it. I also find my self really board with doing that over and over again, but yet I continue to work on having her move off my leg. How interesting, I find it.
So What I think happens is that we get way too focused on the end results of riding. (Mine being that my horse with out attachments that I am pushing her way too much). How many of you truly find that happening, no matter what your doing? Yes we need a goal to work towards, and yes I have reached that goal with my horse of leg cues, I still keep going. So next is to see how well it goes with no strings attached, and guess what she does great. We as humans need to get over the fact that just because we can do it, that we should over use it. I was doing a exercise for my teacher the other day, and he asked me to spiral down word. So down I went, but my horse was slow at it, because I had been over using that tool so there for it became ineffective. I had to go back later and redirect it. So don't get too exited that since your able to do one thing that you should do it all the time.