The usage of the pronoun I is not innate but acquired. At first, Infants use their proper names to refer to themselves. It is so difficult to master the usage of I that it takes a long time for infants to know how to use the first-person pronoun. When, how and why did we get to use the first-person pronoun?
We come across two sorts of incompleteness if you regard language as means to represent the world faithfully and communicate it to others. This incompleteness is, however, necessary for us.