Day 9 of 365: Identifying with Form

How do we identify with form?  When I was in school, I recall a period during finals where I must have worn the same sweater for over a week.  I don't know that I shaved either.  When I finally did switch it up and wear a different sweater and shave, there was a little shift my experience and to be honest I had started identifying with the sweater in a way.  I was, after all, wearing it every day.  I have found it interesting to contemplate what this may imply about how we relate to the body in general.  After all, why do we call it my body?  Because we are in our body every moment of every day (unless we are spaced out), we tend to take the experience of body as a confirmation of our existence.  I think we do this with little things all the time: favorite sunglasses, a watch we never take off, etc.  What happens when we lose those?  What happens when we move to a new home and our external world changes?  We may feel some sort of change in us.  What's to say that our body is any more "me" than our clothes?  Anybody see Invasion of the Body Snatchers?