I suppose one might feel how much they owe their parents is a reciprocal of how much their parents were there for them in the past.
My mom keeled over dead from an aneurism, so I didn't have much I could give her in return other than pulling the plug when she was declared brain dead. My father had a short 6 week bout with cancer and had to be in nursing home and hospital, so all I could do for him was manage his affairs and make sure he was comfortable. Towards the end, I told him if he was my dog I'd have put him down weeks ago. He said not to worry because it wasn't that bad. After 3-4 cardiac events where he kept renouncing his living will, he finally accepted he wasn't gonna make it, and I made sure he was pain free at the end. If it was legal, and he was incapacitated and couldn't make his own decisions, I'd have put him down. He let me off the hook for that. Thanks, pops.
My father in-law had dementia for the last 2 years of his life, but fortunately, he was a happy one, not an angry one. My mother in-law was able to care for him at home. But the last month, he became too week to help her by standing up and walking to the bathroom so she could clean him up, and she was too weak to carry him, or pull him up out of his char. Plus, he kept getting up out of bed and dancing around the bedroom at night yelling about how great and young he felt. So weird. Too weak to stand when awake, yet so strong he could dance for half an hour at 3:00am. She could no longer handle him, and while we were waiting for his COVID test so he could be admitted to Hospice, he passed away.
As for their legacies, mom had everything planned and he and my father had their financial affairs in order and were ready to retire when she died suddenly. She never got to enjoy retirement. My dad started dating a woman after mom passed, and they traveled a bit, and did social things, but he died just 6 years after my mom. His will was short and sweet. One of my siblings and I were co-executors. Everything was split evenly between the five of us. Took about a year to get it all settled. Thank goodness my siblings didn't argue about anything. I think we're all closer now because of that.
My father in-law and mother in-law got to enjoy a long happy life together. He got to enjoy about 28 years of retirement. She still worked another 13 years, but had massive vacation time, so they traveled, took cruises and train rides, went to Europe, etc... and took us to Hawaii for their 50th and our 25th and my sister in-law's 15th wedding anniversaries.
Mom's affairs are in order. We've been discussing her wishes as she gets older and we're going to be the ones taking care of her. Right now, she's fine with living alone. She said if she can't, she'd like to go to a group home instead of a nursing home, but that will depend on her health when it comes to it. For now, we see her at least twice a week. We go there for dinner, she comes here for dinner. She goes to the casino and visits friends and has a social life.
I won't mind taking care of her if I have to, as she did so much for my wife and our kids over the last 43 years. I helped her with her folks as much as I could, and her husband. She's always been thankful. So it's a two-way street, I suppose.
Anyhow, everyone's situation is different. Good luck to all of you in this situation.