We are always more anxious to be distinguished for a talent which we do not possess, than to be praised for the fifteen which we do possess. Sometimes we are too close to the scene, to see clearly. We "know" ourselves so well that we cannot see how we are perceived by others. Our opinion of ourselves is only "one" opinion and it may not be the truth.
All you need in this life is ignorance and confidence; then success is sure. You can "already know for sure" things that could actually impede progress. Always be on the lookout for the things you did not know, that you did not know. Secondly, work on strengthening personal belief that a particular will be achieved regardless of any adversity that may show up, or evidence to the contrary.