The excellent Paul Jarvis made this great point in an episode (#23) of the "Shut Up Show" with Berni Xiong and Phil Gerbyshak. Fear is a natural by-product of pushing the boundaries farther than we deemed possible. It lessens as we acclimate to its daily appearance in our lives but should never go away. Safe and comfortable translates into stagnant lives. Redefine fear as the unknown instead of the dangerous. Your challenge is to convert the unknown into the known. Only then will you know what you can accomplish.