Can I relate a couple of bullets that I've managed to dodge? Because of my past caregiving experiences, I'm (hopefully) determined not to rinse and repeat.
My father wasn't in my life very much, but not because he didn't want to be. Multiple events led to an on-again-off-again relationship. The last time it was on-again, in the meantime, he'd developed a drinking problem/gambling problem/contracted untreated Hep C. Sigh. That wasn't the man he'd been before.
He occasionally asked for money from us, which I refused after having to nag him to pay back the first loan we gave him. I wasn't willing to subsidize his drinking/gambling. At one point, he wanted to move in with us. (This was after my grandmother had passed, so my experiences with her were still quite fresh.) I told him that he was never going to live with us because of his problems. I still cared about him, but I wasn't going to expose my husband and kids to the difficulties those issues would cause. My family came first.
His health continued to decline and he died at 67 about 11 years ago. Of any regrets I've had, not taking him in is not one of them. In his final months, he'd arranged home health care for himself. If he'd been with us, that wouldn't have been enough, for details I won't disturb you with.
One bullet dodged.
My FIL and SMIL are still both living at 86 and 78, respectively. Of all their 5 remaining kids, (1 of hers died a few years ago at age 48, they had none together), my husband is the only one who stayed nearby. The others all took off for different states right after attaining adulthood. We live 45 minutes away.
They're both declining, her more rapidly over the last year or so. Now, despite my previous caregiving experiences, I might have been inclined to help out somewhat. My kids are grown, my husband still works, I am available. But...
We're like sandpaper rubbing together. You could light a fire with the friction between us. There are a few reasons. However, the one that's most relevant is that when I gave birth to my first child - their first grandchild/step-grandchild - they did nothing to help this brand new mother, even after I fell sick within a few days of giving birth. (I'd probably picked up a virus in the hospital.)
At the time, we lived less than half an hour away. They were the only grandparents in my newborn's life. Weren't they supposed to dote on her, be ready when I needed advice, or a much-needed break, in those early days? They were already retired, at 62 and 55! But, no. They wanted to be grandparents in name only, I guess. I was sick. My newborn was sick in a different way - I later learned she had a milk intolerance at the time. They would not involve themselves in any way. I was frantic and worried.
But guess who did help? My grandparents. They were 76 and 74 at the time! They came to my rescue one day, when my husband was out of town for work. I desperately needed to buy some soy formula (at the doctor's suggestion) in the hopes that my daughter would be able to keep something down (she did keep the soy down and started to thrive). After that, my grandparents came once a week, every week (until my grandfather's death), for 4 hours to visit their first great-grandchild and give me a bit of a break.
My FIL and SMIL felt (and still do feel) they had the right to criticize, but no desire to lift a finger to help. Nothing changed with the birth of my son, either. IMO, it's shameful when people their age (mid 50's to early 60's at the time) wouldn't help, while a couple in their 70's dropped everything to be there. Needless to say, my grandparents didn't like my in-laws much.
So, all these years later, I feel absolutely no desire to help my FIL or SMIL now. They can pay for any help they need. They haven't asked, AFAIK, but my husband knows my feelings on the matter. (If I did try to help, I'd probably be criticized to death during the process anyway.)
Dodging bullet number 2, so far.