I completely understand how and why you feel the deep seeded desire to create a persona. You want to fit in, yet want to protect the real you from being hurt again. I do the same thing, often without consciously being aware that I'm doing so. Then, when the person gets too close, I close myself off and they lose interest in pursuing a friendship/relationship.

It's frustrating, and I often grow hostile towards others as a result of the frustration. I try and tell my therapist about this, but the discussion often moves away from this subject matter all to quickly.