This reminds me of a commercial where a pregnant woman and an old man are sitting on a bench waiting for the bus. She's got something on her mind so the old man talks to her and she admits she's anxious about the future. He tries to reassure her kindly. Then the bus comes, she stands up, and tells him,
"Come on, Dad, the bus is here."
The old man is confused for a moment but you can tell the man giving her that advice has now vanished. He doesn't remember his own daughter and she's trying to keep them together. I think about it almost every time someone mentions Alzheimer's.
Sometimes, however, I get a break with Don Knotts, who even as an actor had a perpetual confused look about him so it hits a little less hard.

NGL I just felt sad when gyuha said that they kissed in the morning and now Cha's got amnesia..so many people wake up to something like this with their partners Alzheimer's and I'm glad it's not a permanent one for these two