T-Rex: It has come to my attention that I have different interests than I did when I was a child. In many significant ways, we are two different people.
T-Rex: So the questions is:

T-Rex: Who am I?

T-Rex: Since an individual can "evolve" over time, what makes them a person at all? Is there no connection between myself as a child and myself now, besides the fact that we share a (now post-pubescent) body?
T-Rex: What is the point about worrying about the Self if the Self is in a constant state of change?

T-Rex: Why should we bother assigning an identity to what is essentially one frame of a constantly-changing motion picture?
Utahraptor: T-Rex!

Utahraptor: I think you are overanalyzing this. People change, that is part of life. Just because we're in a state of gradual evolution doesn't mean we have no identity; indeed, that identity is probably what's guiding the evolution.
T-Rex: You raise some good points. However, you forget one crucial thing.

T-Rex: NOBODY ASKED YOU!