We are the sum of our decisions, decisions made based on a purpose we think we have.  With a purpose for our being in mind, we chose and continue to choose our path.  But the path is not a straight one, unless we decide it to be so.  It is not stagnate, unless we decide it to be so, and it is not our only destiny, unless we decide it to be so.  Most folks like what they have become and just stay in that space for a lifetime.  Defaulting to optimism, it would be safe to say that those same folks know they can make a new decision tonight and drastically change the sum of who they are and what others perceive as what their purpose is before the sun rises in the morning.  But turning to pessimism, those same folks would most likely make those decisions in an emotional state. The fragility of life, what it becomes through the acting out of ideals at random moments in the course of less than a hundred years, is determined first through thoughts.  Thoughts spawned though emotion, that morph into a physical action producing a real result.  A result that may affect one or millions.  The key, then, is to become the sum of mature, well thought out decisions, ones made with a clear mind, a mind that has been trained to be just so.  A meditated mind.