person A: I can start to see my mother showing early signs of dementia. I feel really helpless about it_comma_ since it shows how vulnerable they are. I try to help with small things_comma_ but it's sad knowing I won't be able to slow down the effects of it.
person B: That's very sad. My Grandma had that and it is devastating to experience it. I'm told that doing puzzles etc. keeps the brain active and maybe at least delays it.
person A: I heard that too! I try to do some of those here and there_comma_ but I get kind of tired of them after a while when I'm not successful. I'm really just dreading her getting much worse and not recognizing me_comma_ and having it seem like the past never happened. 
person B: I really feel for you. It's not easy_comma_ I won't kid you. But at least you understand what's happening and are obviously prepared for the inevitable.