I really agree with this. It IS all about the mind. I used to be the typically "lost for all hope" AFC (not that I'm a master PUA now either, but I try my best). Then, some one year ago, I decided to make a full turnaround.
It's easier said than done, but I've learned that you really can be anything you want (exept perhaps a lotto-millionaire, but those sort of things are hard to accomplish without a teeny part luck

), if you can convince yourself to believe it. If you want to be confident, there's no magic trick to it, you have to make yourself know and believe in that you are good/smart/charming/etc enough.