"Faking it" may have been the wrong words he used in reference to what he really meant? I say that because I believe when we lack self confidence that we need to practice behavior that attributes to confidence. Is that really faking it? Maybe, at first~
A person may slouch, talk quietly, avoid people, etc....If you are aware of these traits you can change them though you still may lack the confidence. A person can stand tall, smile more, talk a little louder, and make himself go in public more~
Practiced behavior then becomes habit and these specific habits can lead to a true confidence~
You should never change your personality; it is who you are, but ENHANCE it! 