Having been a rather sickly and awkward boy, I was as a young man at first both nervous and distrustful of my own prowess.

I had to train myself painfully and laboriously not merely as regards my body but as regards my soul and spirit.
When a boy I read a passage in one of Marryat's books which always impressed me.

In this passage the captain of some small British man-of-war is explaining to the hero how to acquire the quality of fearlessness.

He says that at the outset almost every man is frightened when he goes into action, but that the course to follow is for the man to keep such a grip on himself that he can act just as if he was not frightened.

After this is kept up long enough it changes from pretense to reality, and the man does in very fact become fearless by sheer dint of practicing fearlessness when he does not feel it.