Art & Identity

If our identities are ultimately hybrid, then is our American ideology of continual self-reinvention valid?  At some point in a person's life, parts of their identity become fixed.   At some point we have to choose who we are and stand up for that choice.  Or do we?  In the background of this conversation about identity and art is the everpresent spectre of existentialist thought, throwing doubt and confusion into the mix.  What's the point of claiming an identity if you have no control over how long you get to live?  Or how you'll be remembered?  I think that's another important part of identity.  How long does it last?  How long will stories be told about each one of us?  When does identity end?