I find it interesting that some people who know their death is imminent want to hurry it along. I had a friend who knew he would die in a few days from a fast-moving cancer who whined, “why can’t I just die now” a day or so before his death. Similarly, my aunt, dying of another fast moving cancer, was asking to go just days before she did.
On the other hand, I’ve seen some hold out for years. My mother-in-law stayed alive for six months, lying in a bed, unable to move a muscle (due to a stroke), unable to hear a thing, and clearly in horrendous pain.
I think depression plays a role in this. Some are used to thinking about suicide, but don’t do it because of the impact it will have on others they love. Finally, a release will come. The pain will be over. Who would begrudge a few hour headstart?
There are people who face this: people who are about to be executed. Their choices are somewhat limited, but it might be interesting to find out how they spend their last days. I think it is traditional to give them any meal they want. I doubt if that is a real promise, but still, it’s a nice myth.