Nisargadatta's "I Am That" - chapter 1The Sense of 'I am'.
Questioner: It is a matter of daily experience that on waking up the world suddenly appears. Where does it come from? Maharaj: Before anything can come into being there must be somebody to whom it comes. All appearance and disappearance presupposes a change against some changeless background. Q: Before waking up I was unconscious. M: In what sense? Having forgotten, or not having experienced?
A lapse in memory: is it a proof of non-existence?
M: Even to say that you are not the body is not quite true.