Our deepest fear is not that we are inadequate.
Our deepest fear is that we are powerful beyond measure.
It is our light, not our darkness, that most frightens us.
We ask ourselves, who am I to be brilliant, gorgeous, talented and fabulous?
Actually, who are you not to be?
You are a child of God. Your playing small doesn't serve the world.
There's nothing enlightened about shrinking so that other people won't feel insecure around you.
We were born to make manifest the glory of God that is within us.
It's not just in some us; it's in everyone.
And as we let our own light shine, we unconsciously give other people permission to do the same.
As we are liberated from our fear, our presence automatically liberates others.
- 1994 Inaugural Speech of Nelson Mandela

The above excerpt from Nelson Mandela's inaugural speech highlights a common psychological dynamic that can dramatically impact our ability to enjoy life. Many people are afraid of being big and there is often a very good (and generally unconscious) reason for their fear. While "playing small doesn't serve the world" it can be a logical response to particular life experiences, particularly those of our formative years. If our survival or perceived survival as children depend on us being small, inadequate, compliant, selfless, or even invisible then that's what we learn to do. By adulthood this behavioral adaptation becomes unconscious and can impact our life in a variety of negative ways. We may not feel entitled to success, love, or happiness, we may not be able to set boundaries with others, we may be frightened of exerting power in our intimate or professional relationships, or we may struggle in maintaining our sense of self under certain circumstances or with certain people.

By understanding and making conscious the behavioral adaptations that can cause us to stay small, we can overcome our fears of being big and lead richer and more fulfilling lives. Therapy can be very useful in guiding people through this process.