The unspeakable.

"You can't speak about that which is prior to speech".

This is the difficulty that is Advaita. It points to 'THAT' which is the current state prior to language develpment, even now - so all language fails here.

I read a statement by a language professor who said, something to the effect, that language forms (or supports) our beliefs. In this case that is true. When we say 'I breath' or 'I see' it leads us to continue to believe that we are responsible for these actions. If that were true then who is doing the breathing during sleep? No 'we' are not doing the breathing, seeing, hearing, digesting or any of the manifold bodily activities that go on twenty four hours a day, while we seemingly get on with life - as John Lennon sang - "life is what happens to you while you're busy making other plans". And even the 'other plans' are not in your control - they are just happening.