Some people believe in the dichotomy of the body and the mind while others believe that the physical body (i.e. brain) is the only engine that drives our consciousness. I cannot deny our physical form: the atoms that make up our body behave in specific ways to produce certain molecules; these chains of matter comprise the tissues of our bodies, and in turn, derive our behaviour as a result of their exposure to the environment. From this, then, we are led to believe that our behaviour (and consciousness is a behaviour) is the result of predetermined physical phenomena. Simultaneously, we cannot ignore that matter is constantly flowing. The food we eat and the air we breath to power our bodies become a part of our bodies and therefore our bodies are constantly being replenished. In a quote from Alan Watts, he claims that "not a single atom exists within us today as the atoms that comprised us when we were children." In a way, then, we are constantly shedding our bodies.
How can that be true?! That we are our bodies, while at the same time, we are constantly leaking 'old bodies'.
This confusion is the result of looking at the question of what we are through two different lenses. It is important to acknowledge that the lens you look through will change your perspective but it doesn't change the reality. What I've deduced is that the physical (i.e. matter) is the medium through which we exist and our existence is dependent on specific combinations of atoms that are constantly flowing. In many ways, we are like a wave in the ocean. Is the wave a result of the water? Yes, a wave is only observed in the water but simultaneously the water and the waves are different. The physical universe is our ocean of matter and I am a wave and you are a wave.
To you, I wave hello.