Positive self-esteem operates as, in effect, the immune system of the consciousness, providing resistance, strength, and a capacity for regeneration. When self-esteem is low, our resilience in the face of life's adversities is diminished. We crumble before vicissitudes that a healthier sense of self could vanquish. We tend to be more influenced by the desire to avoid pain than to experience joy. Negatives have more power over us than positives.
Nathaniel Branden (1992). “Power of Self Esteem”