As a pointer, some non-dual teachers say: you are not a separate being.
That simple statement points to two distinct things.
I am not a being. To myself, I am capacity for the world as it appears to me, and this includes this human self and anything connected to it. It all happens within and as me. To others and in the world, I am this human being. To myself, I am capacity for this one and the rest of the world as it appears to me now.
I am not separate. Similarly, since the content of my experience happens within and as what I am, there is no real separation between anything. When I find myself as capacity for the world as it appears to me, it’s oneness noticing itself as all there is. We can make distinctions through a mental field overlay of images and thoughts, but these are no real distinctions.
So when I hear that I am not a separate being, it’s really two things. I am not a being. And what I am does not have any real separation in it.
Of course, this doesn’t negate our ordinary human and conventional experience of the world. In the world, I am this human being. And in the world, I am somewhat separate from others and can experience myself as separate and even alone and experiencing loneliness.