Does Culture Change Who We Are?

Is it possible to remain true to who you are when you work or live in an environment that is different from you? Do we naturally adapt or adopt as a way to survive? Most of us believe that we do indeed adapt in order to survive. Is there a point of no return? That is, can you stay so long in that place and not become one with the existing culture? By staying too long do you lose yourself...Does who you are disappear to be replaced by a clone? How long is too long?