when this child is born, he has totally no idea of everything that is going on around him, but he has that capacity to learn. and learn he does.
he learns that he has feelings. he feels uncomfortable when the nappy is wet and soiled. he feels pain when he is hungry. and these feelings creates sensations that are uneasy.
he learns that he can see. and the sights he sees for the first time are all so interesting. some of these sights capture his attention more than others, creating a feeling of joy, which in turn creates a tingling sensation in his body which makes him at ease.
then he can hear, the voices of his parents singing a lullaby. the mishmash of sounds and voices all around, though confusing, fascinates him. bit by bit he learns to differenciate these sounds and voices, and is able to recognize and put them in order.
there's also the sense of smell, taste and touch. and all these 5 senses aggregates into perception. with perception, he learns and categorizes everything he experience and gives everything an identity.
and so there is form. and so every moment he begins to interact with all the forms that he perceives, giving rise to an array of feelings for these forms, and with these feelings arises volition. the will and intentions; reactions to the different feelings.
and there is conciousness. awareness. that which gives rise to the rest and at the same time is created by the rest.
a voice called out.
voice: aiyo baby geis wake up already ah. geis u guai guai ok dun cry mama go get milk for u.
sight and sound: beautiful being (form) making sounds to me.
that beautiful being carries him and feeds him milk, and the sense of touch that is so comfortable. he is happy and will continue to react the same way to this form.
and soon he learns more. he learns the being wants him to call it mama, and mama calls him geis. and so he becomes geis as a result. and then with time and more experience he believes and it becomes natural that he is geis. it becomes more and more apparent that there is geis and there are others, and geis becomes separated from the others.
and thus, from the 5 skandhas, the ego is arise.
(impt note: ego here refers to to the perceived self, and is not 'real')