Are we this body, or are we mind? Or, are we both mind and body?

Or something other than these both. We have a physical body that has 5 basic senses, it helps us to react and interact with the outer stimulus. This physical machine is subject to constant change. It is not a single object but a collection of millions of cells, dying and Forming each second. Some consider this as the ultimate truth. Then there are our thoughts, memories and emotions that is experienced by the experiencer itself, the consciousness. This is also subject to change, as our emotions, thoughts and ideas change moment to moment. Some consider This forms our mind. Some consider this mind as the ultimate truth. But the question of who am I still remains. Can we attach our true identity to something that is in itself changes every moment. Of course not. And what is the problem of accepting this change as the answer to our self. Just as the changes of the planks of ship still points to the same ship, Similarly our changes still point to ourselves. This change is the essence of our existence. Or is there something behind mind and body, something that illuminates both. I am not saying This is in religious or spiritual sense. But these are some tough questions which I find very hard to find an answer.