Afraid of Success

I think I've begun to notice a pattern where I'll work hard just to have an opportunity for something (get a job offer, meet a new person) then back down right when I've secured that thing and need only take the next step to secure that job or becomes friends. Why am I afraid of getting what I once desperately wanted? Marianne Williamson writes about fear of success:

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 we not to be? You are a child of God. Your playing small doesn't serve the world. There is nothing enlightened about shrinking so that other people won't feel insecure around you.

This may be more to the case of not wanting to intimidate your peers...sometimes, I won't give an answer in class or group study because I don't want to seem a "know it all". But with regards to other goals when I really could achieve them, why would I rather sit quietly in my room? I think there might be a connection. Maybe it's time to start exploring why I'm seemingly accepting a life of sub-happiness by choosing to stop before my goals. I think I may have to self-reflect on this. My one thought now is that it may be we as people get comfortable in our cycles, even if there are higher objectives that we'd like to reach. When I stop before the finish line...maybe I'm just afraid of a change in the routine?