When my siblings started to visit in the last year, they would all comment that they felt they got dumber just by being entwined alone with my parents.
It’s more so my mom that will ask you where she put everything to the more complex scenario where she is adamant that she gave you the grocery list and be so compelling that you start to feel the fog descend down around you. Your thinking starts to slow, you have trouble remembering what day it is and your start to second guess your own sanity. When you plan to go out, while there are only three of you, you have to tell two of you so many times where you are going that you are exhausted before you have even left the house.
When my parents called to ask me what day it was, I was at home. I answered the question and was happy that they called. After I hung up, it struck me that my parents were totally unable to manage to figure out what day it was. It was in the middle of the week and I can see how you might lose track of the day in a moment, but there are so many cues to assist you in figuring it out.
They get a newspaper, have a TV, multiple calendars and my dad has a computer and a mobile phone. Last year I gave them a clock that actually tells them the day of the week. Alarmed.