“Whatever we expect with confidence becomes
our own self-fulfilling prophecy.” — Brian Tracy

This is no less true when we expect other people to succeed,
expect them to do things correctly, expect them to give everything they do
their best effort. You are surprised when other people make mistakes, give
things less than their best effort, don’t succeed. Since you expect success,
you assume personal responsibility for mistakes of others, lackluster effort,
non-success. Your first take on the situation is that you haven’t been smart
enough or skilled enough to effectuate the right outcome. You then work with
the person to identify the deficiencies. You modify your performance so that
you better facilitate the other person’s success.