My father died on my birthday (12 July) 2010 after a few years of suffering Alsheimers. I was in Cyprus and didn't see him in his last days, nor did I go to his funeral (for practical reasons).
It was pitiful to see my Dad in his last few years. He was always very sharp mentally (he loved to do algebra problems as a hobby) but once my Mum died a few years before he just 'switched off' and became mentally and physically incapable. He was brought up with a strong christian belief (PB not JW) but to be honest I'm not quite sure just how much he really believed it (WWII experiences and losing his first wife at 25 must have dented his faith). I hope, for his sake, he did.
Two years before he died my two brothers and I went to see him in the nursing home (it wasn't in the UK and took some coordination). We took with us a photo album compiled of all the old photos we could get hold of and spent hours going through it with him. It was a depressing experience - there wasn't much there.
By coincidence, the afternoon we visited the nursing home was the afternoon the local vicar came to hold a 'service'. By further coincidence, he was a Welshman from the area my Dad grew up. My last 'real' memory of my Dad was that afternoon, his three sons holding his hand (he was in a wheelchair) as we sang old Welsh hymn tunes. I thought I saw him smile but I can't be sure. That was the last time I saw him.
I am an atheist, but I hope my Dad died clinging to his beliefs - otherwise so much of his life would have been wasted. I think he looked forward to an eternal life straight after death and if that sustained him, good for him. I don't know how he reconciled in his mind (but I bet this had been on his mind for man, many years) the question of whether he would be his first wife and true love, or with my mother, his second wife. Perhaps this was one of the questions best not pondered too long.
periodtgreen, you have my sympathy. I said goodbye to my Dad a couple of years before he died. Even then, he wasn't the Dad I knew and even then I chose to remember him as he had been. Be thankful for the good memories - they will outlive the bad.
Regards.