Our early training and our self-centeredness combine to make us
believe that every judgement of us is about us. In fact most aren't.
This is a rare case where being less self-centered will make people
more confident. Once you realize how little most people judging
you care about judging you accurately—once you realize that because
of the normal distribution of most applicant pools, it matters least
to judge accurately in precisely the cases where judgement has the
most effect—you won't take rejection so personally.
And curiously enough, taking rejection less personally may help you
to get rejected less often. If you think someone judging you will
work hard to judge you correctly, you can afford to be passive.
But the more you realize that most judgements are greatly influenced
by random, extraneous factors—that most people judging you are
more like a fickle novel buyer than a wise and perceptive
magistrate—the more you realize you can do things to influence the
outcome.