Not being completely separated from others, what is that about?

You could compare your mental existence with mushrooms: under the ground there is a large structure of fibers, however, these you do not perceive. This web of fibers, the mycelium, is the actual plant. Here and there an occasional mushroom will appear above the ground, as a seemingly unique and independent being. However, it is the fruit of this web of fibers.

In this analogy you could see the inner Self as the web of fibers, and bodies as mushrooms. A body thus looks like a seemingly independent being, however, it came into being through the web of fibers, of which it is still a part.

When you see it like this, what you perceive with your physical senses as 'someone else' is nothing more than a limitation of your perception to what is 'above the ground'. You say: I only see mushrooms so 'therefore' they are separate beings. Thus forgetting that they are only fruits of the essence which is in the soil, and are not even plants in themselves.