What a person believes about himself and his abilities is a self-fulfilling prophecy. A person who does not consider himself "important" will not free himself from negative habits.
Believing you are inferior, untalented, unimportant or incapable, influences your abilities. If you view yourself as unable to do things, you will be unable to do them. On the other hand, if you see yourself as talented, capable, and important, your self-concept will open up powers and talents that would have otherwise remained dormant.
Hardly anyone utilizes his entire capabilities. We can accomplish much more than we realize. By raising the perception of your capabilities, you will accomplish more.
(see Rabbi Aharon of Karlin - "Dor Daiah," vol.1, p.167; Rabbi Pliskin's "Gateway to Happiness," p.116)