My mother, 95, has had memory glitches for several years, but mostly things like word retrieval or someone's name. I just rolled with it, but recently she has started losing bits of common factual knowledge, and this caught me by surprise.
For instance, while playing with my cat, she suddenly asked if all cats had whiskers. She said she had never noticed whiskers on a cat before. Now, we've had cats in the family off and on for seventy years, and I can remember her scolding me as a small child for trimming the cat's whiskers with scissors.
Or here's another: she's a lifelong gardener, very good with plants, but recently I realized that she was thinking that an annual plant was one that bloomed only once a year --- not one that lived only a year.
About the same time, I noticed that she was losing memories of place/direction --- what the doctor's office building looked like from outside, which way to turn to go to the library. This was really noticeable, since she has always been a ferocious back-seat driver and navigator, and she has suddenly stopped warning me to change lanes a mile or so before every turn.
So ... in what order do people usually lose memories? Are there types of memory/information that are more or less likely to go first? Last? Does this change in what she remembers mean anything in particular, that is, does it mark a stage in the decline of memory or does it depend on the individual?