To begin with, you are without knowing that you are. There is no comprehension or incomprehension, there is simply experience and feeling.
Then, gradually, vapours of thought condense, a kernel of self-awareness crystallises, and a nascent layer of linguistic understanding accumulates. A new I has entered the world.
There is then a period of play and exploration. There is boisterous exuberance, an untrammelled joy at being and learning.
Then, at some stage, one discovers that one has been born into a system:
"Why do I have to go to school?"
"To learn things."
"Why do I have to learn things?"
"So you can get a job."
"Why do I have to get a job?"
"So you can make money."
"Why do I have to make money?"
"So you can buy things."
"Why don't we just give people money without making them work?"
"Then nobody would do the things people don't want to do, to make the things to buy."
So, grudgingly, we enter the system. After some years, however, a second existential transition creeps upon us. Not only is each I born into an external system, but each I is incarnated in its own animal system, and that animal system is programmed to reproduce. Previously dormant mental systems and hormones kick into action, and suddenly it is these body systems which are in control, the I simply a means to realise their imperatives.
A re-interpretation of the external system then takes place. It becomes a system to be played to our advantage to satisfy the physiological exigencies. Money will provide not only food, drink and shelter, but a means of attracting mates, and a means of rearing progeny. This second existential transition converts most into an acceptance of the system. Many are consumed by ambition from this point on. The world for most is then a world of careers, families, mortgages, bills, and pensions. A world of planning, rules and systems.
The joy and spontaneity of the young I is a barely acknowledged mote of memory.
And then a third existential transition creeps upon us. The internal system begins to decay and fail. The reproductive drive shrivels. The layers of linguistic understanding erode, and eventually even the kernel of self-awareness becomes brittle. Thought evaporates, and only feeling and experience remain. At the end, you are without knowing that you are. Beyond, there is nothing.