Even if life is meaningless, you still only get to do it once. Sometimes its more fun when playing on cheat codes if you know what I mean. If life is meaningless then its impossible to fail because the failure had no meaning to begin with. It is however possible to succeed by setting out a goal and accomplishing it. There lies the fundamental difference. The meaning of life is determined solely by the individual and not an exterior presence. You give your own life meaning based on how important of emphasis you place on your goals. If your goals are meaningless, then so is life. If your goals are meaningful, then your life is too.