Reality is immense. Reality exists with or without us.
This is the utter truth which wise men through the ages have been trying to say to human beings of all ages. This reality is the perennial background of the story of mankind.
Against this ultimate reality is the narrow perception of the world according to individual human beings.
We come into being the moment we gain consciousness.
This is regardless of the view of other people of us. They may have seen us toddling around at infancy but we may remember nothing. We remember from a certain age and it is that certain age that we have our consciousness - and memory.
As we grow older, wisdom comes as layers and layers of consciousness - our realisation of the different aspects and degree of the perennial reality.
But there is a difference between the moment of consciousness/memory and the moment of our realisation of the different aspects and layers of reality.
From birth, we are conditioned by our caretakers to survive as a member of a social unit and as a specie. It is only when we come into realisation that we are each an individual that we come into our own individual being. Instead of being a pre-programmed robot, we try to re-programme individual ourselves. It is that tweaking of our in-built programme that we come into our own being, in the way of imagine ourselves to be.
As a result, we also reinvent our own world. The larger reality exist by itself irrespective of us, but the way we see the world and the way we interact with the world is defined hopefully by ourselves, but most of time by the society in which we find ourselves in.
If we disagree with our pre-conditioning, then we have know how we want to re-condition ourselves by the principles by which we want to live and by the habits which we want to cultivate. This is where all the talk about the examined life and the cultivated or cultured man/woman comes in.
In redefining our individual selves, we are in fact putting our selves together to make ourselves an individual whole. This recreation of self is necessarily ego-centric. But the existence of self does imply that one will be selfish although one is likely to be. The existence of the ego does not mean that one has to be egotistical. The sharing of self with other selves is not selfish, although it may be seen as egotistical but it is really up to the individual to know and deal with it personally and privately.
Once the self is sorted out, the rest of the job of living is simply to survive bodily with the least psychological stress. This is contentment and happiness. The self is settled and one can sit quietly and permanently like a stone, without a care in the world and most likely without a thought of any kind.
But the moment a thought enters the mind, mental activity takes place - which is likely to be concerned with the external physical world, and with the inconveniences and aesthetics of the body and with the problems of the cohesion of societies. This is where the inventions of the mundane world come in.