Yes, I do. Sometimes the elderly become depressed and when they are, their mental and physical health problems are enhanced and exaggerated to the point they feel as if they are going to die. However in the case where they instinctively feel as if they are going to die, I think they are truly realizing the coming of the event. We know we begin to die the day we are born, constant chemical changes in our bodies occur without our noticing. One chemical change is our "Fight or Flight response. It's my opinion that as we near death the flight portion of the autonomic nervous system controlling the response diminishes and we are not equipped to fight and surrender to the threat. I feel at that time our organs slow to the point where they are near exhaustion and with that resignation, our minds and spirit are no longer able to control our destiny and we expire. The above are my thoughts and is based purely on my personal suppositions.
I think it is very possible that they do in many cases but not most.
Yes,i do think everyone knows the moment they are going to die not the day but the instant before they do they realize their not going to draw their next breath.unless it is a instantaneous death (no time to even think).