Thanks for that"Why only last few minute memories disappear"
This might help
Dementia bookshelf analogy - Abacare Blog
The Jersey Alzheimer’s Association is expanding people’s knowledge of dementia with its ‘bookshelf model analogy’ to help people understand the condition.abacare.org.uk
Im afraid that there isnt much you can do about it. All you can do is tell them about things as you need them to know them. And just accept that anything you say will get forgotten.