Act upon it just as if it were true!

The most important psychologic discovery of this century
is the discovery of the "self-image." Whether we realize
it or not, each of us carries about with us a mental
blueprint or picture of ourselves. It may be vague and
ill-defined to our conscious gaze. In fact, it may not be
consciously recognizable at all. But it is there, complete
down to the last detail. This self-image is our own conception
of the "sort of person I am." It has been built up
from our own beliefs about ourselves. But most of these
beliefs about ourselves have unconsciously been formed
from our past experiences, our successes and failures, our
humiliations, our triumphs, and the way other people have
reacted to us, especially in early childhood. From all these
we mentally construct a "self" (or a picture of a self).
Once an idea or belief about ourselves goes into this picture
it becomes "true," as far as we personally are concerned.
We do not question its validity, but proceed to act upon it just as if it were true.