The only essential ingredient for doing the impossible, outside of talent, work, dedication, perseverance, luck and strategic support, is faith that you can do it.  

Lose that spark of sometimes unreasonable hope for success and the world is right– what you are trying to do is impossible, a million reasons it was doomed from the start.  Tongues will cluck, sad looks pass behind your back.  Life will go on, just not for your dream.

Depression, it emerges, is like riding a bike.  Don’t do it for 25 years, find yourself in the right situation and, bingo:  no training wheels needed.