So what is this Self? Who exactly are we? The aShTAvakra gItA has much to say about our real nature. One sutra claims the following:
You are not the body, the body is not 'yours'. Sir, you are neither an 'enjoyer' nor a 'doer'. You are Consciousness itself, the eternal, disinterested witness - be happy!
Our problems are caused by what Advaita calls adhyAsa, meaning 'superimposition'. As a result of our ignorance, we fail to see the truth that is in front of us, so to speak. The classic metaphor tells us that it is as if we encounter a rope on our path but believe it to be a snake. We are deluded by what is called mAyA. The 'veiling power' or AvaraNa prevents us from seeing the reality of the rope, while the 'projecting power' or vikshepa superimposes the image of the snake. Similarly, we are prevented from seeing our true nature of eternal existence-consciousness-bliss and instead superimpose the false image of 'little me', living a very limited, miserable existence and doomed to extinction.
In reality, there is only the Self. There are no 'others', no objects, no separateness of any kind; no time, space or causation. All of these things and concepts are mistakes produced by our mind in its ignorance. A metaphor used to explain this says that it as if we see all the waves in the sea and believe them to be separate entities, not realising that they are only transient forms of the one, undifferentiated ocean. Gold rings, necklaces and ornaments etc. are each perceived as being unique. But if a ring is melted down and made into a bangle, it is the same gold as before, merely assuming a new name and form.
So with us. We believe ourselves to be separate individuals with our own body and mind, unique and vulnerable. But these are only name and form of the one, undifferentiated reality, which is Consciousness. As Ramesh Balsekar says: All there is is Consciousness - Consciousness is all there is. We also believe that we are 'doers' and 'enjoyers' and that we have free will to enable us to choose how to act.
Unfortunately, it is not possible to think or talk about 'reality'; it is beyond concepts or words. Indeed. it is the mind and its concepts that prevent us from realising the true nature of reality. Space, time and causality are three of the concepts that we use to try to make sense of the world that we believe we perceive but they take us away from reality rather than bringing us closer to it. There is only 'now', nothing changes and memory is perhaps the cause of all of our problems as Time, Change and Memory points out.