Memories determine how you will act/react to a set of circumstances, ultimately leading you to go in a predetermined direction. This direction is in reality determined by your past experiences. If you want to change your future, you have to change your thoughts, and thus your actions.
Unfortunately our memories will betray us into acting out of fear rather than boldness. To create new pathways, we need to mutter to ourselves what we hope to accomplish. Talk to yourself as you create new patterns in your conscious mind. These new patterns sink down (forgive the metaphor) into your subconscious mind.
In your subconscious mind your new thought patterns will create tension with the old patterns. Change is always resisted by the old guard. This is the real battle. To overcome the old patterns requires extra work, extra effort and energy. Most fail to accomplish their dreams simply because it is too much like "work."
Changing your paradigm is fundamental to accomplishing your dream. Success or failure starts in your mind. Change your thinking and you change your future.