The Self is (first) to be realised as existing, and (then) as It really is. Of these two (aspects), the real nature of the Self that has been known as merely existing, becomes favourably disposed (for self-revelation).(Ka.Up. II.13)
Two parables of the Self come to mind. The Tenth Man relates how a party of 10 travellers were crossing a dangerous river. Having got over the leader of the group counted them to see if everybody was safely over. He counted nine and began to bewail the missing one until a passer by reminded him - ‘you have forgotten to count yourself, you are the tenth man’. Applying that inclusion to the population of the mind it is evident that while all the elements of the stream of consciousness iare counted in the Humean way the counter is not counted.
What is salient is the shock that presents the existence of the Self. You must have the Coleridgean deep thinking as deep feeling experience which is entirely different from the sureties of vapid prattle. We recognise that all mental events, thoughts, perceptions, experiences etc. are saturated with ‘self-ness’ but yet the self is not them. It persists, they pass.
Another koan like parable is the torn sugar bag of John Perry. He relates:
"I once followed a trail of sugar on a supermarket floor, pushing my cart down the aisle on one side of a tall counter and back the aisle on the other, seeking the shopper with the torn sack to tell him he was making a mess. With each trip around the counter, the trail became thicker. But I seemed unable to catch up. Finally it dawned on me. I was the shopper I was trying to catch.
The trail becoming thicker seems to me like the building up of duration in Bergson’s sense. All the previous meditations on the series of conscious states gain a critical mass and evoke an insight into the self as an existent.
Follow the sugar.