Cognition depends upon conceptual compression: we are able to carry in our minds compressed, simplistic notions that we then expand as needed for use. One of our most natural compressions is that a human ontogenetic organism has a self. This assumption makes perfect sense to us. From the viewpoint of cognitive science, it is amazing that an organism that spans scores of years, with the most dramatic changes, development, and transformations, from birth to death, should have a unitary sense of self. Evidently, this conscious cartoon of the self keeps us going. Cultures invest in propping up this useful conception: for example, they give us persistent proper names, providing culturally-enforced linguistic continuity across otherwise remarkable variation.
Ron Sun: Grounding Social Sciences in Cognitive Sciences (2012)