What does it mean to be born? What does it mean to die?
It is impossible to verify whether you were something before you were thrown into the world (born) or you will be something when you are thrown out of the world (die). The world is the place where we know we exist (we are something here and we are aware of it) and this existence is filled with thought and sensation. Thought has a limited structure (e.g. we are aware of thinking our own thoughts) and is filled by sensations from our limited senses; our ability to think and sense are both generated by the process of being born. The structure of thought and the senses fall apart when you are thrown out of the world. Therefore, you were nothing that could experience before being born, in life you experience and then you become nothing again.
Why do we try to grasp nothingness? It is because of the value of the something we have in life. Instead of trying to understand the nothing and built comforting religions to cover up the “horror” of not knowing, allow the hard edge of experience, beyond which “no traveller returns”, to reflect back to this life and to the state in which you exist. As Heidegger says, thinking of our birth and death brings us face to face with what we have gained in being born and what we will lose in our death; in other words, it brings us back to ourselves as we exist in this present moment. This means being aware of things like Parkinson’s but also seeing this as only a part of you.
“Our little life to rounded by a sleep” but what is important is being awake when you live this life in this world. Live the dash!