Originally Posted by Lenin
On the other hand I imagine a heart attack or stroke might wake one up rather abruptly
Not all heart attacks or strokes are that distinct, though. When my late husband had his heart attack, he had just finished cooking dinner. When he first started showing symptoms something was wrong, I asked, "Do you think it could be a heart attack? Should I call 911?" His answer: "No. I cooked dinner. I'm going to eat it!"
We were about half way through dinner before I reached the conclusion it was likely a heart attack and called 911. My husband sat and finished his dinner as he waited for the ambulance to get here! I guess he wasn't looking forward to hospital food.
(Incidentally, he did survive another ten years.)