What ever you are saying is Dementia, where in pateints above 60 yr ol develop this condition they forget todays and yesterday and recent incidents but will only remember old or past incidents they can't form new memories. So usually they get irritated. Your mother needs support from family members with repeated reminding if things so, treat her like a young child where they can't do things on their own and consult a psychiatrist for more adivce and if needed medication.