When you use the word 'I', it implies that there is someone looking out of your eyes, someone located in your brain that thinks and feels. This I is seen as seperate from all the other I's that live on earth.

But what if this was like a desert mirage that looks like water but is not water? Is there some one here, or is there no one here?

And if somehow there was an awareness that no one is here, what would arise? How would your body/mind function?

Self-enquiry cannot answer these questions. The logical mind cannot grasp it... and yet it can be known.