Self image psychology is the rage these days. California creates a commission to raise self esteem and feeling good about yourself underlies New Age cures. We attribute "self-image psychology" to the late Harry Stack Sullivan, but when Heraclitus said, "Character is Destiny", he anticipated Sullivan by more than a millennum.
In the early 1940's a sociologist named Merton coined the phrase "self-fulfilling prophecy", by which he meant expectations that create reality. In the bright light of hindsight, the validity of Merton's observation is self evident. Expectations or limitations we impose on ourselves generate behavior.We do not attempt anything we see as beyond us.
Self-image psychology resembles a magician's illusion that lifts us by psychological bootstraps, but for all the faith, there is logic. Living according to expectations turns self-image into a self-fulfilling prophecy. To make our prophecy true, we become the person we think we are.