The general question is to ask "who are we?"
For the sake of simplicity, I will use "I" instead of "we" to invoke the thinking process.
Am I the thoughts? am I the set of ideals and beliefs? Am I the memory? what define me?
Am I constant in time? whatever I experience, the observer seems to be the same. Probably I am the observer. But what is the observer inside our physical body? It lives inside brain. It does not go out of brain if we move, implies it is related to the physical body.
Is it the physical body? but it changes with time. After years, I won't recognize myself in the mirror. I will look different. So, I am not the body(provided the 'I' is constant in time).
If we are not the body, then what are we? what defines us? are we unique? or are we different than all?
Is the observer universal? or is it local? If it is universal (it lives in different dimension than space-time, such that it has access to all these things and it remains unaffected by space-time), it has to only interact with a living brain and then we are all related inderectly. We are all one. We are the same. We are the one observer for the universe itself and we exerperience or perceive things differently due to different set of memory and experiences in different bodies.
If we are local and unique, then we are different than all. We are the observer for our own self. We are the one who perceives things differently than others, then only the exchange of ideas between individuals can reveal the objective truth.
Think, who are we? think!!! for the sake of knowing.
But, when we say who are we, we want an answer. We will try to find a thing which describe us, what if that thing or idea does not exist in our world.
We have insticts, thoughts, emotions, feelings. We see colors, hear sounds, smell odors, taste foods. All these things could be unique to us or univsersal with zero to little variation.
The world does not contain colours,sounds, taste, odors, experience of touch, as the world is made up of matter (or fundamental particles) in space time with certain physical laws. The world is dark place. It is our consciousness which gives us the experience of colors, sounds, taste, odors, touch. You can use phyical forces to explain touch, chemicals to explain the taste and odors, longitudnal sound waves to explain the sound, and electromagnetic waves to explain the colors. But these are not the experience of touch, taste, odors, sound and colors. These are just the physical explanation of how we perceive these things. The experience is unique to us. It is our consciousness which gives us the experience of these things.
There is huge gap between the physical world and our experience of the world. The physical world is made up of matter and energy in space-time, but our experience of the world is made up of consciousness. The physical world is objective, but our experience of the world is subjective. The physical world is external, but our experience of the world is internal. The physical world is public, but our experience of the world is private.