The only answer I can come up with (though it may be an overrated Mean Girls reference) is that they pushed me.
They pushed me past all the limits I thought I couldn't overcome. They taught me not only copious amounts of facts, but they taught me how to think for myself and how to solve problems on my feet. The were continuously pushing me to be better than the person I was before I stepped into their classroom. In all honesty, sometimes I really disliked them. It frustrated me to no end when I couldn't just ask them for the answer or when I had to do so much research and work to find one simple answer. However, now that I'm older, I've discovered that the reward for being pushed to work so hard and think so much is much greater than the frustration I endured.
Not only am I forever thankful that these educators where beyond brilliant in seeing and believing in all the potential every one of their students had, but I am thankful that I have such great role models to look up to today as I work towards becoming a marvelously, frustrating teacher myself.