Agreed. The same can be said about lifting of course. A lot of people work out and leave some in the tank. What kind of results do you think they get? Few, few is the right answer. Compare that with the kid who goes in, goes ape shět, and leaves it all there at the gym. Who prevails in the end? The guy who went balls to the wall, who went into that dark place where he abandoned his body and his needs and went all the way, through the pain and self-doubt, all the way to the end to reach his goals.
Back to your point, though, you definitely have to do that with any of your fears - face them head on - in order to succeed. All fear does is hold you back in life. To experience fear is completely natural, but to not expose yourself to certain things or situations in life because of fear is to have phobias. These neurotic behaviors just lead to an abandon of any drive to live. Engage your fears, expose yourself to unfamiliar situations, and you will become stronger, happier, and succeed in life.