My first pony, Shorty, actually taught me the most. He was a trickster, and I did not have a saddle, so did everything bareback. He would run under low limbs, lean your leg on a fence, and he went where HE wanted. But I learned how to overcome all this, and taught him to jump, and we would jump a barrel with 2 tires on top, just a 2x4 rail that he could have gone under, and he was only 12.1 H !!!
As far as people, Fran Dearing at Windy Knoll Farm, hands down. I took lessons from her in 1982, then came back in 1999, and we just picked up where we left off. She communicates riding without using all the "in vogue" terms, and actually celebrates horses outside the norm doing dressage. She NEVER limited anyone to "lower level"!!!I trained Appaloosas, Paints, Arabians with her, and she always encouraged me to make the most of THAT horse. Great woman.