My father is now in a nursing care center but even before this, he would have 2 days where he was more alert (meaning awake) and then he would have a day where he would hardly have his eyes open but yet he would ramble on. he wasn't sleeping but his eyes were barely slit open and I knew (know) it would be a down day. But I have seen other patients at this facility that hardly go thru this process.....what is the difference or does anyone know? does it have to do with the stage of dementia they are in?