One of the things that I've also noticed is that my wife always walks behind me, not even with me or ahead of me. At first, I didn't catch on but after a few weeks of doing so, I finally realized that she was purposely lagging in stores because she didnt want to take a wrong turn or lose sight of me. She also does not like looking at pictures pr watch family videos. I think part of it is that her short and long term memory are effected. I also think that it makes her upset or sad, which makes her cry, get a headache, and shut down (long periods of sleep). I learn new things about this disease almost daily on how it effects the person who has Alzheimer's.
My heart goes out to you. I'm sorry that you lost your mom and had to witness the symptoms of dementia. My mom also had dementia bit would never admit that she needed medical care.