I had a teacher who was always on my back, constantly. Same situation. But she told me, much later, "I wanted you to really apply yourself, because I saw potential. We have to be better to be considered just as good. It may not seem fair, but the other kids already have their champions. We have to push our own, too." I never forgot that, and even though for me as a teenager it was a drag, as an adult I respect it.