There are ways of paying attention, of being in the present, and that comes with observation. Have you ever watched an animal intent on this moment? They are not "thinking" of the past or worrying about the future. It is now, and now only, that interests them. Whether it is the prey they are after or the flower they seek or the trail they take, it is the moment they are in. Or have you ever watched a baby eating ice cream? They are in the moment, the only thing in the world is the enjoyment of that treat.
We big apes tend to obsess about things, worry about things, think about what "may" come to pass and forget to be in this moment. We have things to do, lists to fill, projects to complete and honestly, I think that is all fine and good. I do that too. But if I am sitting down and enjoying a well cooked meal or watching a sunrise or the birds in the yard, or enjoying a cool drink, I want to be in that moment. To savor each and every beautiful thing about that moment.
And when a crises arises, I have no choice, I must be in the moment to deal with the emergency without panic. Imagine (out of this moment now) that one is off somewhere in the clouds and not paying attention then you can see how accidents happen. We trip, we fall, we crash, we burn when we are not watchful and in the now.
As many wise ones have extolled through the ages, this moment, this experience, what is happening here and now is all there is and continues ad infinitum. I get out of the moment but I am just wandering about aimlessly in my head, out of body kind of, but that body, this presence is still here and I am just distracted by passing thoughts or some emotion that arises.
The real clarity of mind when it becomes clear as crystal is when you are in this moment. The clouds disappear, the mind focuses on the pinpoint of understanding and actually accepting of what is.
Is it possible? I mean, is it possible to stay in the moment? As I said before, I can't and I have heard that no matter how enlightened a person is, it is always a (I don't want to use the word "struggle" so...) "journey", a constant trekking along the path that is life. It is not a straight line, a beginning or an ending, it is a meandering, stopping for views, falling into potholes, climbing to see a vista, tumbling down cliffs, rising to a dawn...and on and on. This moment has no ending, no beginning, no boundaries, no limitations, it just is what it is. (A quandary? Perhaps, if you try and figure out what "it" is. hah!)
I think Alan Watts, who very like Paul Reps the haiku-ist, brought Eastern thought and philosophy to the West (and were both outlaws, and my heroes, in their respective fields), said it most succinctly about "this moment."
"Life exists only at this very moment, and in this moment it is infinite and eternal, for the present moment is infinitely small; before we can measure it, it has gone, and yet it exists forever...."