In terms of timelime, our thoughts can be categorized in either the past, the present, or the future.
I have recently found most of my thoughts in the last category, forgetting about what was around me. The well written post Live Now makes a good point about the importance of the present moment. While thinking of the future gives a sense of direction, it is uncertain, and one cannot experience and truly live in the future. The same holds for the past, as it is already done, and immutable. Both are important, and not to be forgotten, but the present is where we currently are, and is affected by what we currently do.
Living now allows us to fully live and not to worry about what was and what will be. Living now allows us to make the best decisions based on the current conditions. Living now allows us to be more mindful, and be happy, now.