There is an old Zen story I like.
A junior monk asks a senior monk, "Where is Zen?"
The senior replies, "Do you hear the sound of the river?"
The junior monk replies, "Yes."
The senior monk says, "Enter there."
I have a lot of fun studying neurology, epistemology, ontology, semantics, and a variety of other subjects. (What can I say? I'm a geek.)
One of the things that becomes clear, particularly if you follow the work of Robert Anton Wilson, or Alfred Korzybski, has to do with levels of abstraction. Humans deal with several levels of abstraction. The most basic way to differentiate them is to split abstractions into lower and higher. Lower abstractions are the immediate, physiological processing of stimulus translated into simple urges, sensations, and reactions. Feelings, inclinations, flight-fight responses. Higher level abstractions, which humans are particularly evolved for, would be languaging, conceptualizing, thinking, and digesting input.
The thing that becomes clear appears to be that once an event comes to human awareness, it is already an abstraction. By the time we have a handle on it in anyway the stimulus has already been sorted, processed, categorized, and labeled.
This is particularly evident when we are thinking about something. But, even in every day life we can see that "chair" is an abstraction of sensory input of form and color, coupled with cultural conditioning. "Chair" is an abstraction we learn.
It works in the same way for anything that we have a label for. The label is a convenient placeholder, or structure of input.
What we deal with, as humans, on a conscious level appears to be nearly 100% abstractions. We don't handle reality, we interface with it.
As far as I can tell there is only one exception to this rule. Pure being. What I mean by that is the raw sense that I am, the root of what I call "me." Once we remove all abstractions from that, it seems like it's the exact same sense you get when you feel your own being. As far as I have been able to find in conversations with people the basic sense of being has only one flavor. Of course there's kind of a trick there, since the moment we talk about it we are dealing in abstractions. Still, as far as I have been able to come to mutual understanding with others, the raw sense of being is the same everywhere for everyone.
That is why I like John Sherman's suggestion so much. It asks us to take a look directly at the raw sense of being in order to shed some light on what we really are.
Do you exist? Do you feel a presence of being? Put aside history, and context. Put aside labels, and concepts. Can you feel what it is to be? Enter there.