Alzheimer's

Two weeks ago I went to Tokyo to see my sister. She is retired from university, but at the same time she suffered from dementia. Let me read the definition of dementia. "Progressive memory loss is the hallmark of dementia. Initially, only short-term memory is impaired, and the person seems merely forgetful. This can interfere with the ability to interact socially and perform work. Long-term memory may be retained, often in great detail, but eventually fragmented as the disease progresses. The person with dementia may or say something over and over again. In most cases, he or she is probably looking for comfort, sinceriy and familiarity."
I took her out to a Japanese retaurant. In the beginning I was relieved to hear her speaking like a real professor who is at the podium. She was so articulate. Having said that she repeated that she became the emeritus professor five times. No, she is not proud of that. That's a symptom that she suffers from Alzheimer's. Moreover she even mistook me for my brother who died a couple of years ago. We left the retaurant and went to her apartment. I handed her "Yokan" (sweet beans) as souvenior. As I was about to leave her house, she was curious about "Yokan". She forgot that I just gave it to her. Since her husband died 9 years ago and she has no children, I decided to go see her from time to time.