The now is all you have and is all you will ever have. The past is our faint recall of emotionally charged events. The future is a hope, a dream or a nightmare. Everything you see is through a filter. A filter created by your past experiences and expectations of the future.
Embrace the moment and give it all that you have. Use your senses and live in the moment. Know what you are seeing, feeling, hearing, smelling and tasting. Be an observer of the world inside and outside of you. Do not attach yourself to these emotions and ideas. Things are always changing and if you are in the now you will notice this.