You are there - present. You know you are present. You have always been present. No matter what the experience is, you have been present.
There is a presence - that presence is here now. It has no particular attributes to speak of - it isn't red or square or soft. It is just here now. That's it's attributes. It's here now. It's not identifiable or personal - those are given to the body, to feelings, to thoughts, to roles or names or whatever. That presence is just there regardless of the state of the body or thoughts or feelings or anything else.
What you call "ME" at the deepest level is just that presence which is always here - that "subjectivity" or subjective presence - it isn't objective - it doesn't appear to get a look at it. It cannot appear to get a look at it because it is the LOOKING - the knowing - the quality or capacity of knowing.
So we can say that the purely subjective nature of presence is knowing. That is what you are - right now - that presence is subjective and that really means it is the knowing. We cannot SEE knowing because seeing is knowing. We cannot get a look at the knowing because we are looking FOR it with the instrument by which we look, yes? So the knowing is the purely subjective presence.
That doesn't change - if the sun rises that is known. If it sets that is known. Those are two different experiences yet the subjectivity involved in that experience was changeLESS - yes? The subjectivity or presence or knowing "OF the sunset" - that was the same in both experiences - in fact we really cannot even say that because to say they were the same is to have previously quantified or qualified that presence and then later compared it to the second experience. We cannot even do that - this is PURE subjectivity - PURE knowing.
So that really means that this presence you know so well, HAS NO CONTENT. It has nothing to grasp. It has nothing to contribute objectively to any experience. It is simply the present knowing or presence of knowing which really is a redundant way of speaking. The presence IS the knowing. YOU are the knowing in each experience. That is your quality no matter what the experience is.
So if there is a stomach ache - you are the knowing OF THAT - the stomach and the pain and the thoughts about it are ALL objective - you know them. So the body and thoughts are objective. Right this instant, the body is not what you ARE! Thoughts are not what you are! Why? Because that presence is there unchanged while the body and thoughts are objective happenings - experiences. You are the experiencing OF the body and thoughts - the capacity FOR the experiences we call "body" and "thoughts".
When you were a child, that presence was there - exactly as it is now. The surroundings have changed - the body has aged - lots of things have changed EXCEPT YOU - YOU remain the same - present and aware.
Notice this - don't try to make it into anything. Just notice it. Notice that pure knowing in every experience - notice that it is purely subjective, and then notice that it's YOU.