I think there are some very good points above..
here is what I think..
my dad died only just over a week ago (many of you no doubt read the earlier threads - on life and death decision and no father on fathers day)
While the whole family including my dad denied openly that he was dying, we all kind of knew it and it wasnt until the last two days that we pretty much accepted it. The doctors had been subtly (and not so subtly) suggesting palliative care almost from the time he entered the hospital and we resisted it. I still believe we made the right decisions at the right time and only agreed to palliative care only the last two days.
One of the last things my dad told me was that it just depressed him to look around the four walls of the hospital and think that he may not make it out of there. So if we had given up weeks earlier that (I think) would have it would have been 3 weeks of that for him.
and yet, I think I knew that the end was beginning only a few weeks before when he suddenly lost his balance (due to his low bp) even while sitting down in a chair (his bp was somewhere in the 50s or even 40s at times) At the same time he had lost a lot of interest in life, mainly because he used to be so active and had to catch his breath when walking only a few steps to the next room.
I think there is something to be said for the idea that the loved ones dont want to let go, and when they finally do the dying person can finally go too. There are heartbreaking moments of goodbyes being said.. my dad with great effort on his last night looked directly at me and gave me his hand and then shook my brothers hand - as painful as the memory is it was a real gift to be able to do that.
I also took some opportunity for him to make short video messages to my daughters - they are only 3 1/2 and 18 months ..
so hopefully one day they will be able to appreciate them.
hopefully this helps, but then again, I had a tough time accepting it until it really was obviously happening.