I think it is true that so often more people than not find themselves focused too much on one of two things: the past, or the future. Both of which we have no control over, and both of which are not part of life right now.
Many, including myself at times, are dwellers of the past. It is so easy to get caught up in the way things were, especially when some of those times feel like they were the best you will ever have. Some moments in life are ones you wish to hold onto forever, but it is possible to hold on a little bit too tight, to the point where you are stuck in the way things used to be. There are also people that cling to the past, but not because of the good. Instead, there are some things that with every ounce of your being you could go back and make a change. Unfortunately, that just is not the case. It is okay to look back, but you can't get stuck, because life will just keep going forward.
Some people focus too much on the future. Now, it is very important to plan ahead to a certain extent and take steps necessary to get to the place you want to end up one day. However, sometimes this is taken way too far, obsessing over a time in your life that is not even here yet, which really does not do you any good. Focus on what is right in front of you, not what is miles and miles ahead. Enjoy where you are at, not where you may be going someday.
Living in the past or in the future is spending time in a place that is not now, not the time where you actually have so control over your life, some say. Live in the now, take in the people, the moments, your surroundings, all of it. Take in the good, take in the bad. Go explore and make memories.
The most important thing is to take advantage of the opportunities you have at the moment and to make the best of all you have been given. Whatever you do, just be sure to live in the present. There is no other time like it.
Do not let yourself be held back by events that do not even exist yet or ones that once existed but do not anymore.
There is a quote by Jim Elliot that goes, "Wherever you are, be all there". I love that. I think that is something we all could listen to, and can try to live our lives by. Open yourself up fully to your present surroundings.
It is good to look forward and to look back sometimes, but make sure to not live your whole life there, or be held back by it. Live in the moment, live for now, because you never know what you might be missing, and because you cannot control anything else.
Life goes by pretty fast; if you do not stop and be present, you will miss out on quite a bit.