Congrats. I see it as a very big deal! Its an amazing feeling to have a horse go from fighting and seeming unhappy with the idea of carrying a rider to have a horse become completely relaxed and intune to your every movement. Its the difference between expecting the horse to ride for you to seeing what you can do to help the horse through your riding. The horse becomes much more willing when you take their physical well being into consideration. The funny thing is, he was probably thinking the same thing about you that you are of him!