How we are missing this moment?
We are missing this moment by not being present in it fully. This is mainly because of our constant engagement in our mind, either in memory or in imaginations. And this is not accidental that most of us are continually engaged in our mind, there must be some significant reason behind it. The reason is that we are taking ourself to be someone existing in mind only, so we need to constantly refer to the mind. This way mind is our world and we rarely experience the reality of life, which is essentially outside of the mind. Mind is capable of storing only image of the real experience, it does not have capacity of experiencing it. So normally what we call our experience is going through the image of the real experience in the mind, we are never face to face with life.
Real life is most dangerous place and most safe too. Dangerous because everything is changing constantly so you cannot hold on to anything; safe because the one who is seeing everything changing is always constant. This seer of everything, your true self, is the only constant thing in life. But because we are not able to see the unchanging seer in the constantly changing life, we become afraid of real life and afraid of any type of changes. This constant seer is always present and can be discovered in the present moment.
How to come back to this moment?
One clue is that find out what is constant in you. This is common sense that to experience changes there need to be someone constant who is not changing. So if you find what is in you that does not change in any situation, you will reach to your true self.
Another clue is that find out who is the experiencer of everything. Through this exercise your attention will move from the ever changing life to the never changing seer of it. The experiencer of life is one so it doesn’t matter which experience you choose, you will essentially reach to the same experiencer.