It is time to pick up one of the topics we've been reading in Zen and the Art of Motorcycle Maintenance (ZAMM) by Robert Pirsig. There are LOTS to choose from, so let me see if I can find one that can lead into several others.
One that has been popular with philosophers for generations is the problem that exists between what seems to be a physical world around us and what seems to be a non-physical entity inside us, which is our mind. The existence of a non-physical but seemingly real thing like a mind (or consciousness, if you prefer) doesn't seem like a problem, except when you try and explain how a non-physical thing interacts with a physical thing like your body. How does that happen, exactly?
We have absolute knowledge of our minds, right? We think, and we know the contents of those thoughts intimately. We aspire, dream, fear, worry, and have all sorts of innate and internal conversations with ourselves that form our personal space, our personality, and by some accounts, creates the human experience. How can we translate that sort of experience into a description of what is happening inside our bodies? Is this just a complex series of chemical reactions? Does it happen at nerve endings and nerve connections? Is it related to the proteins in our cells? What?
Some have concluded that the essence of our mind is something like a Spirit, or non-physical entity that somehow comes from outside our bodies. Others have suggested that consciousness is an emergent property of complexity, and that sufficiently complex systems will eventually become conscious. This is the basis of the experience of Ewa in the movie Avatar, where the planet is "alive" in a way that is above and beyond the simple fact of being host to plants and animals. The Mother Earth idea writ large, as it were.
It is hard to escape the idea that each of us represents the entirety of what we are; that all we are is composed of what we can see in the bathroom mirror when we step out of the shower. How can there be more than our physical bodies? It is the Identity Theory applied to people: Bob = Bob. How can it be that Bob = Bob + Mind? The Mind part is already implied and included in the idea of Bob.
Mind/Body dualism. A perennially puzzling problem.