Understanding the notion of “self” abstracted from the ‘I am real’ experience
The word ‘self’ verbalises part of the experience of non-relativised real presence condensed or concentrated to unit status (via the elimination of boundary), objectified as ‘I am’, then iconised (i.e. compressed and abstracted) as ‘I’.
In short, the experience and verbal expression of ‘I’ stand for the whole experience ‘I am absolutely real without limitation’ (hence whole, i.e. a whole unit).
It is the ever present (i.e. continuously presenting and all pervading) ‘I am real (complete, therefore whole, because not relativizsed)’ experience, variously described as ‘I (am real) without a thou’, ‘The one (real) without a second’, ‘The undifferentiated, unborn, uncreated real I am’, which the ancient (East) Indians called the atman (Buddhist: atta, both words possibly derived from sattva), brahman or prajpati. The ancient Israelites described the experience of the undifferentiated ‘I am real’ experience as ‘I am that … I am’ = Yahweh.
The ‘real unit (boundless, because not relativised, hence whole or one) of I am’ experience happens as a continuum (of discretely discontinuous non differentiating contact moments), and precedes relativisation (i.e. differentiation (Sanskrti: with strands or threads, i.e. gunas, Buddhist: sankaras), the latter providing the ‘I am’ (or self-) experience with identity (i.e. identity = difference … that makes a difference, hence gives ‘birth’).
It is the identified ‘real I am’ experience, i.e. the discretely discontinuous and differential continuity of absolute real presence + differentials (hence the atta or atman with clothes (See the Brhad-aranyaka Upanishad)) which the Tathagata (i.e. the Buddha) called the false ‘I am’, i.e. anatta. He claimed that the false ‘I am’ (or atta) was false because the differentials that identify it (i.e. as a persona in real-time) arise (or emerge, due to conditions) momentarily, then fade (i.e. merge) and are extinguished, thus causing dukkha to those who cling to the differentials. He claimed that the differential bits that identified the ‘real I am’ continuum, i.e. the atta, were not (i.e. could not possibly be) the atta because they were the cause of pain and because one had no control over them. Plainly, his reasoning was naïve and seriously incomplete. The problem would be resolved later by the inventors of the Upanishads who proposed a nirguna (without differentials = conditions) Brahman = atman and a saguna (differentiated with gunas = conditions) Brahman = atman.
Because of the pain (indeed death) produced by the differentials (or attributes, i.e. the transitory sankaras), the Tathagata proposed the complete elimination of all attribute bodies (such as the khandas or fetters, or the desire for difference, hence life/birth = death) of the false (because differentiated) ‘real I am’, thereby returning to the true (because undifferentiated) ‘real I am’ = atta. In short, he instructed his followers that they eliminate all difference (hence identity), hence life itself (i.e. all emergent phenomena), thereby avoiding the pain of death.
And the means of eliminating the attributes was first to become wholly indifferent, absolutely non-responsive to those attributes (and which he called ‘blindfolding mata’ (= mara, ‘The Evil One’)), then to refrain from generating (i.e. giving birth to) attributes. By becoming wholly indifferent = same (since sameness is not inconstant (or so it appears), hence cannot be the source of dukkha), the identifiable individual eliminates (or fades) her identity and by so doing reverts to the undifferentiated, non-identifiable (because unborn via attributes = differentials, hence not subject to death) to the ‘real I am’ experience as formless, pre-attribute (Sanskrit: gunas) ground state.
Obviously, that only happens if and when the adept achieves one-pointed-ness of mental focussing (experienced as the perfection gear or speed), expressing itself locally as psychosis (read: cessation of mental functioning).