Why Are We So Hard On Ourselves?

A senior manager at the school stopped me today and asked how things were going. He said, "you really seem to be doing well." I told him it was all a front, but thanks... The Head of the Science Department was walking behind me, so he stopped her and said, "she seems to be doing very well." And she replied in agreement. Why is it that I feel like I am a crap teacher, why am I so hard on myself??? Anyway, Good is nice and the compliment is nice. :) Someday I want to be called an outstanding teacher... But for now I will settle for "good."