My mother-in-law is suffering from dementia, but at age 90 is otherwise healthy apart from some respiratory problems, so her 7 kids are taking 24-hour shifts with her so she can live at home. She gets very frustrated about having to put up with the supervision, though sometimes she is lucid enough to be upset with herself because of the sacrifices her kids are making to do this. My wife and her younger sister have it especially tough because they both work full-time (and often overtime) and then have to give up 24 hours each over the weekend.
It's tough when your parents get old. My dad has Parkinson's and you can see it wearing him down, even if his medications control it. Or maybe he's just getting old and the Parkinson's has nothing to do with it.
Funny, but I don't think he really started to live until he retired. He and my mom started doing work for a prison reform group and gained quite a lot of respect and publicity for it. All the things he's most proud of are the things he and my mom did together after he retired.
Somewhere along the way their relationship changed, though. I always thought of my dad as being so strong and always the smart one in the family. Between the Parkinson's or whatever, he's aged a lot faster than her. It's amazing how much he relies on her, now.
I don't know what he'd do if something happened to my mom. In fact, I'm not sure what she'd do if anything happened to him. I didn't grow up in a very demonstrative family, so I don't think I ever thought much about their relationship with each other. I never realized how much they love each other.