Moment

I am getting to hear the term 'Living in the moment' a lot more times now a days than ever before. You get to read these quotes from philosophers like you have to live in the present i.e. do not be too anxious about the future and  too sad for the past. To this point, its just easy to get the gist and let go. But, sometimes when I think a lot of it, I happen to create for myself a great deal of confusion. Now, consider one way of looking into the matter-

I have observed myself and other people a lot in this aspect (believe me). Now, I don't have any means to comprehend what is going on in other people's mind. I can just relate and compare it to myself. So, when we talk about living in the moment.. what exactly is that?

if we use the term 'experience' for the time when some event is occurring. And 'feel' for the feeling we get from it. For example when I am experiencing a chase by a big dog, i am feeling fear. So is there any real moment when both these things are happening at once? I think when I am running for my life, I am constantly being oscillated between the anticipation of next fearful moment and the memory of past fearful moment. From the extrapolation of the memory of past events, I am anticipating the feeling I would get the next moment. So, I think there is a chance that there is no function in our brains that enables us to live in the moment literally. 

How might the perception of time be occurring inside our brains? Continuous or in the form of very short and discrete moments, too closely packet together to differentiate at normal time pace? (analogy of particle-wave nature of light might help?). So, after all if we consider it as one of the possibilities that perception of present moment may be out of the abilities of our brains- it may lead us to the total paranoia. Because, the only real moment, we can say is the moment of present. And if we cannot grasp that, that means there is no real time or 'reality' as we say. Something like our consciousness is always orthogonal to our physical existence. And do we say that everything is alright when we see- at any moment in the retrospect, the limit of  time function when it was approached from memory was equal to (the value?) that was approached from the anticipation?