how do you build greatness

Human beings have been on this earth for the better part of 15000 years, how do we go about being original with so much behind us and so much surrounding us. Yes, we can pick something very specific to focus on but the laws of mathmatical probability state that we will produce something that will show near identical signs and appearance of something that has been done before us. So should we really be focusing on reminding the world of something great that has already happened? I think as designers it is our goal to be creative and try and stumble onto something new and innovative but doing so without losing sight of our goal which in the end may just steer use right into a what of "been there done that."