I believe it means that your past and background have nothing to do with what you are striving for but instead what is important is what you will do that will shape your future because we can not look at the past and regret but instead keep moving forward. It matters because if you get stuck on previous events it can effect you mentally and distort your thoughts when you have big decisions to choose from so don't get trapped in the past it's best to learn from them and make better decisions for the future