I believe that above all things, if you want to develop as an instructor you have to identify what you can and cannot do. We all have strengths and weaknesses and by knowing what they are and working within our boundaries and working to increase our comfort levels we become better instructors.
Admitting our weaknesses seems to be the hardest of all the personal development needs we have. Once we swollow our pride and own up to our weaknesses I beleive we will ultimately find that we were not alone and enable others to better themselves as well.