I wrote a paper once on self-efficacy, did a literature review. Bottom line is, if you believe you can do something, you're more likely to succeed, because you keep trying in the face of frustration.
When I told someone that I am disheartened by jobhunting, he lectured me on how I must be using incorrect jobhunting tactics, and how I did not understand how jobhunting works. He actually had no understanding of my jobhunting experiences, he just assumed I must be dumb and in need of enlightenment from his mighty self.
You know what, explaining to me that I deserve those rejections because I did everything wrong, that is not cool. That is not something I need in my life. I deserve better. I deserve friends who support me. People who put my down are not friends.