Is there a specific moment when one realizes that s/he is going to die? I guess there is; in fact there are many such moments, because once the inevitability of death has been recognized, a whole system denial springs into action in one’s brain trying to undo the realization, trying to forget once again what it has unintentionally remembered.
Sometimes the brain succeeds; only to stumble upon the reality again at some future time. I have seen people survive cancer, terrible car wrecks, even falls from multiple stories; what I have never seen people survive is life. Life is the most fatal of all diseases. Once you are born, you are doomed to die sooner or later. So I have stopped my brain from trying to forger death. I have decided to always remember that I am going to die. And this decision has freed up my brain; liberated it. And with this newfound freedom, I try to make sure that I don’t spend a single moment without realizing that I am alive.
Do all of us sooner or later realize that we are going to die? Yes. Do all of us eventually realize that we are alive? No. It is tragic but true. So many die without ever knowing that they were alive.