First you have what is called ‘atma-bhava’ – that is the ‘I am’ sense. Later, this sense identifies with the form of a body, when it is called ‘aham-akar’, the ‘I am’ form, this is ego. Ego is never a title or name, but just a sense of ‘I am’ prior to words. The waking state, the sleep state and the knowingness ‘I am’ constitute an ego. In the absence of these three states what do you think you are? What would be the evidence of your existence?