I have always been fascinated by the mechanisms behind building up a self-identity. There are many roots to this activity. It occurs to me that one may be a shortcoming in the way the brain processes information.
One of the things the brain does is it uses short cuts. Things it "already knows" do not make as big an impact as new information, because rather than be constantly overwhelmed by new input, the brain stores, categorizes, labels, and recognizes bits of the environment we encounter. Seeing the painting that has been on the wall of our living room for years often makes much less impact than the painting we encounter in a restroom at a restaurant we have never been to before.
New makes a bigger impression.
Perhaps then, one of the reasons that the body surface is seen to be some sort of border between what we are and everything else has to do with familiarity. No matter where we go, or what we do, there we are in the same old sack of skin.
But, that's not true, is it? How much has your body changed since you were twenty? Or, twelve? Or, two? They say that all of the cells in the body are recycled and replaced every four years. We don't notice that process though as it takes so long and occurs within a stream of information we are all too familiar with. Feeling into what it felt like to be you when you were a child is one of the ways you can pierce this delusion.
Perhaps this is one of the reasons that people who have out of body experiences are so profoundly affected. Other than it being a total trip, it unlocks them from the conviction that they are the body. Profound illness can have the same effect. As can the loss of a limb, or a sense.
Rather than waiting for such a traumatic experience, we can question this conviction right here and now. Are you the body? Which portion? What happens when the body is altered? Can you feel what is happening in the body? Have you ever felt your heart race? How can this information be coming to you, if the body is you?
These questions can loosen the hold of this conviction and leave you with only you, and not a contraction into the surface of your skin.