When you have eliminated the impossible, whatever remains, however improbable, must be the truth.

            Arthur Conan Doyle, The Case-Book of Sherlock Holmes

The process of answering the question Who am I?  by removing all that I am not is an ancient path to awareness that you may already be familiar with: the path of reduction – that is, removing layers of falsehood one by one in order to uncover the truth.

If this particular formulation of it is ultimately at odds with anything that you believe after considered reflection to be more vitally true, please feel free to let it go and follow a path that works better for you.

For me, having been led down this particular road, my next insight seemed simply a natural outcome of what I'd already considered and accepted.

Narrowing down who I am seems to result in a conception of myself as smaller than I had previously thought. Apparently, I'm not my body, which is about 75 kilograms (on a good day!). I'm also not my thoughts or feelings, which are of unknown size but seem to take up a bit of room nonetheless. So if I'm actually the one who observes these things, then I'm in some sense a tiny point or particle of awareness that is somehow slipped between and among these things.

I won't venture to say how small: infinitely small, quark sized, photon sized, Planck-length sized – who can say? I chose the words vanishingly small dot to be poetically descriptive yet scientifically vague. It's really just a metaphor, and in this realm – as when asking how many angels can dance on the head of a pin – the concept of size doesn't seem to make much objective sense in any case.

Nevertheless, it's a leap to go from thinking of myself as an observer of some size that I haven't really considered, and then to consider the matter and arrive at the formulation vanishingly small dot of awareness.