There are two basic perspectives in life. The perspective from the absolute and the perspective from separation. 99.9% of people experience only one of them. The experience of separation.
The fact that 99.9% of humans have only experienced separation does not invalidate the experience of the Absolute. Both can be defended, neither can be proved.
There is a personal embodied self which we all know very well. There is the impersonal One Self, without form. We are both.
The embodied self is hard wired to survive, and as long as survival is our primary motive, this is the only self we will ever know. To know the Impersonal Self, one will have to go a lot deeper, and risk everything into the unknown.
Since the path into the unknown, is by definition, unknowable, we find ourselves in a quandary. Very much like a who-done-it, we have clues, but no end in sight.
The major clue we have is the "still small voice" that is heard when we hope without knowing. A faith in things unseen. Unbidden, but there. Not always a gentle voice, as it is often a gnawing in the gut, a feeling that something is missing.
Do we follow the "still small voice?" Or do we resist because we do not know who is calling, or where it will lead us? If we are quiet and listen, we faintly hear, "Go to the tiger's lair, and stick your head in the tiger's mouth."
You sane one's quickly turn up the volume and walk away, so the still small voice cannot be heard in the din. But the crazy one, whom you shun, seeks the tiger's lair, places his head in the tiger's mouth, and shouts,"Bite, you son of a bitch, Bite!"