" Your past is not your potential." 

What i think this quote means is that what you've achieved in the past is not your full potential. Whether you've failed or achieved something you have so much more to give. With time we change, we gain knowledge about things so who we were in the past isn't really us anymore. Your potential expands and increases. When you really want something or really want to be something or someone youll give it your all. We will give so much more than what we gave in the past.