A person can’t grow beyond the self-concept he or she has established in the subconscious mind. Remember the story of the farmer who found a jar in a pumpkin field? To see if the pumpkin would be strong enough to grow and break the jar, he poked a growing seedling inside and left it there. When he went back to harvest the grown pumpkins he found that this one had not been able to break the jar. It had merely grown to mould itself to the size and shape of the jar and then stopped growing. Our self-image puts the same kind of limit on what we can accomplish. If we can expand our self-image we can expand our potential. I believer that it’s a prerequisite: We cannot expand our potential unless we first learn how to expand our self-image.

Source: Roger Dawson, 1994, The 13 Secrets of Power Performance, New Jersey USA: Prentice Hall, p.109