I was sitting on a plane next to an older man, who was telling me about how he had just visited his father, but that it was sad because he has dementia and didn't remember him anymore. I was trying to comfort him, mostly because I worry it will happen to my dad, too.
It's nice that you tried to comfort him.  I'm worried about my parents, also.  It's hard to be worried about something like that in your family, knowing that you have no control over whether or not it will happen.  It's sad.
Yeah. We grow up thinking they're invincible. And then as we get older, we see that picture deteriorate little by little. And then when they get old and need help, a lot of the time we don't have time or money to help them, so it's just stressful and sad all the way around.
Agreed - it's very stressful.  I live half a country away from my parents, and I'm worried I won't be able to help when either of them need it.  