If you doubt you can accomplish something, then you can't accomplish it. You have to have confidence in your ability, and then be tough enough to follow through.
You must accept that you might fail; then, if you do your best and still don't win, at least you can be satisfied that you've tried. If you don't accept failure as a possibility, you don't set high goals, you don't branch out, you don't try - you don't take the risk.
If we have not achieved our early dreams, we must either find new ones or see what we can salvage from the old. If we have accomplished what we set out to do in our youth, we need not weep like Alexander the Great that we have no more worlds to conquer.
I think the city of Washington itself is insular to a certain extent. You have to get out in the country to realize what is going on and discover that the perceptions in Washington aren't necessarily accurate.