One of my brothers-in-law died at age 72 and he'd had alzheimers since he was in his mid 50s. It was very sad to watch him fade away from reality.  He used to LOVE to play cards and board games and we first noticed the problem with him when playing these games, and he would miss an obvious play or do something really out of the norm.  The longer it went on the more heartbreaking it became.  When he went into a nursing home facility because my sister had such horrible arthritis she couldn't walk so was thus unable to care for him, my DH and I went to visit him a few times but he didn't know who we were and it felt so strange for us.  We probably would have gone back more often if there had been even a spark of recognition, but there was none.  When he and my sister were still able to stay together in their home, he would wander off and my niece's husband would have to take his 4-wheeler and go find him and bring him home.  That was dangerous because they lived alongside a very busy "tourist area road" and he could easily have gotten hurt or run over. 

There were no such things as HOME healthcare workers back then, and if you hired a private nurse to come to your home for a whole day it cost 3 arms and a leg to have them there.  Pitiful.