Everyone wants to live an incredible story — the fulfillment of a great destiny. The problem is that we pursue destiny as if it was a late night infomercial. We want riches or the abs without the work or in this case, without working backwards from your destiny > to your character > to your habits > to your actions > to your words > all the way back to your thoughts.
To change (or fulfill) my destiny, I must first change the way I think about the world around me. Before your first memory, your brain started making connections and these hundreds of thousands of connections (interactions and experiences) have become your world-view (the way you think about the world works and how you relate to it). Your world-view is based upon a complex series of assumptions — some good and some very false. The core of all your insecurities are just bad assumptions. Your assumptions are what is holding you back. Impossible is really just a way of thinking.