Also wanted to put in a plug about my dad...
My dad is a workaholic, supposedly had a very rocky relationship with his parents as a kid/teen (he was an only child, they were a doctor/nurse, very hard driving folks who were NOT happy with his career choice until he became a general officer). Yet this man dropped everything to care for his parents when my grandpa was diagnosed with Alzheimers and my grandma went into heart failure simultaneously. He changed their depends, spoon fed grandpa, worked his crazy schedule, but came right home, sold his dream house to fund their care and moved he and my mom into a condo that they shared with them so that there would be someone there 24/7.
Both my grandparents have died now, but now dad cares for his mom's brother. He hasn't moved his uncle into the house yet (because his uncle refuses to move and aside from very mild dementia issues that one might expect at 98 he's in excellent health), but he calls him 3 times a day, coordinates the caregivers, and drives from DC to MA to visit him at least twice a month, and takes his uncle on vacations wherever he wants to go.
This has definitely shown me a side of my dad that I would have never guessed that he has. I remember when I was visiting my folks while my grandma was still alive, getting up to go to the bathroom at 3 AM and hearing my dad downstairs with his mom, reading her one of her favorite books because she'd woken up, was in pain, and he was comforting her until her meds kicked in (she was entering home hospice care at that point, and she died less than 2 weeks after we went home from the visit. I wasn't too surprised, she told me she was ready to go after seeing us and her great grandbaby once last time, and she didn't feel strong enough to hold on for the twins to be born).
My dad is NOT a warm fuzzy sort of guy. But he was absolutely there when it mattered.
Also, when the big Nisqually earthquake hit Seattle about 7 years ago, the FIRST people to run to the daycare I worked at were my assistant's two grown sons. They beat out all the parents! They wanted to make sure their mom was okay, and both of them were farther away from where most of the parents worked.
Also, for mother's day and valentines day, they'd send her roses at work, and were fighting over who would get to have her stay with them when she was getting her condo remodeled.
I told her I was really glad to have HER as my parenting mentor, because I wanted to be the kind of mom she was!!