A.Of the four components that were defined - mind, intellect, ego and memory - each has its field of operation. The mind in the above is the locus of emotional thoughts, classified as nine moods or feelings of expression (nava rasa-s) consisting of love, passion, anger, jealousy, etc. In addition, the mind is also a clearing house for input from the senses and output through the organs of action; it can be thought of as a receiving and dispatching clerk. Furthermore, it is also a 'doubting Thomas', entertaining all the doubts and the associated worries and indecisions. Some people cannot make up their minds easily, because they are dominated by this part of the mind, which is indecisive.
In contrast to the lower mind, the intellect can be considered as the ‘officer in charge’. Being both analytical and synthetic as well as objective, it can hop from the known to the unknown in order to gain knowledge.
the ego involves two aspects - 'I am this' (ahaMkAra) and 'that is mine' (mamakAra) or simply 'I and mine'
. I can reject anything and everything as not 'I' but I cannot reject 'I’- itself, since I have to be there in order to reject anything. This process of sublation or negation is called meditation, where I drop the false I in order to ascertain my real nature.
B.All subject-object (I and this) duality ceases in the deep sleep state, with ‘I’ alone remaining without any inclusions or exclusions, since there is no 'this' and 'that' that I can perceive. Vedanta says that cessation of identification of 'I' with any 'this' is the key to happiness. Therefore, the deep sleep experience points out that there is a possibility of existing as pure ‘I’, as consciousness and existence, without any identification with this or that.
C.When I realize my true nature, these false identifications or notions drop or, more correctly, the reality that I assign to the notions is withdrawn. Then, I will be 'as though' operating as pure self, without any false identification, treating the mind as just a subtle body that I can use to transact with the world, through the 19 gates discussed earlier.
D.All objective knowledge that is gained is stored in the memory, which forms the basis for all recognitions. We can build up our memory bank by gaining knowledge, storing the information and retrieving it whenever it is needed for communication and transactions. New knowledge is built based on the past knowledge stored in the memory. There are two aspects involved: the capacity to store and the capacity to retrieve that knowledge. Retrieval and re-storage keep the knowledge fresh in the memory and those that are retrieved less and less will get buried in the memory and retrieval will also become increasingly difficult.
E.Limitless though I am, I take myself to be limited; notionally, 'I am = this'. This leaves me with three fundamental limitations which can be expressed as a) I am a mortal b) I am unhappy and c) I am ignorant.
When I take myself to be the body, then body problems become my problems. The body, by its nature, undergoes six modifications: existence in the womb (asti) for seven to nine months; birth as a baby (jAyate); growing pains as a child to an adulthood (vardhate); modifications of the body (vipariNamati, i.e. problems of the grownups); slow disintegration with all the health problems in the world (apakshIyate) and ultimately kicking the bucket (vinasyati).
Reference & Courtesy: An introduction to Vedanta - Dr.Sadananda