Mostly when we say I, we are referring to the me-feeling. Meaning the sense of being an individual entity. 
Upon knowing oneself, we refer to I as the ultimate reality of being awareness. 

Although there is no separate self, we are not knowing of our true nature, until we are. 

The waking state is our laboratory of sort, to contemplate and inquire into the reality of our experience and awaken from the unhappy illusion of separation.