Overcoming fear seems to be the door to many new worlds.  The old stories of CrazyHorse coming out of battle having bullet holes through his clothes, but not a scratch on his body, proves that he had total domination of fear.  The fear of dying is limiting in itself and usually results in a fear of living.  One usually has to have a strong belief system, or a total lack of fear itself, to want to go beyond the goal line.  The trust in yourself, and self reliance, does reduce relative fear.  I have been inspired many times to self preservation, through the influence of great fear. I almost died several times climbing a mountain, only to get back to the truck, and want to go do it over again.   Knocking on heavens door.