Have you ever said, "I had to pinch myself," because you wondered if you were really alive, awake, or experiencing what you were seeing or hearing?
One of the closest cognitive experiences we have to mimic death might be anesthesia. Apart from the reality of the spiritual realm our brains do not record pain, pleasure, or any other sensation.
After experiencing and learning to cope with bouts of severe pain, I came to appreciate the quote below:
"Pain is a kindly, hopeful thing, a certain proof of life, a clear assurance that all is not yet over, that there is still a chance. But if your heart has no pain -- well, that may betoken health, as you suppose: but are you certain that it does not mean that your soul is dead?" - Arthur John (A. J.) Gossip