All the greatest men are maniacs. They are possessed by a mania which drives them forward towards thier goal. The great scientists, the philosophers, the religious leaders - all maniacs. What else but a blind singlenee of purpose could have given focus to thier genius, would have kept them in the groove of purpose. Mania. . . is as priceless as genius.
You want to create things as purely as possible without allowing the universe to interfere so much that it's manipulating it and making things unreal to you.