The following was found in an old notebook in the handwriting of a much younger man. I do not know its source.
Whenever in the present moment our mind projects a memory-image from the past, thereby betraying an attachment thereto, our consciousness is torn and divided between the present and the past. It is this division which is the fundamental element of the tension which engenders the 'I-process'. The function of the mind is not to store up memories, but to understand the process of its own functioning in the present.
Schematically the brain could be drawn as a point or centre of pure perception endowed with extraordinary sensibility. Everything happening around this point is continually registered as electro-magnetic perturbations. And though at the beginning they were impersonal and without any individuality, they have become mechanical memories comparable with those of sound recorders.
Finally this accumulation of memory becomes so complex and dense that secondary phenomena begin to appear. The memories become so loaded that suddenly by the natural affect of certain 'law of mass', reciprocal action takes place between the different layers of superimposed engrams. Secondary currents spring up and set of a whole process of 'parasitic' phenomena. The Sages believe that consciousness of self is nothing other than a 'secondary current', a 'parasitical phenomenon.'
Thus an entity has been built up on what was a simple impersonal non-individualized process of pure-perception. It has been erected as a result of the impression of psychological solidity given by the complexity of memory accumulations.