For me, the most difficult “cultural difference” to adjust to in the world of dementia is the fact that the use of reason is strangely – adamantly – not useful. I’ve read stacks of books looking for an appropriate substitute, but, so far, no luck.
The explanation I’ve found goes something like this: Imagine that someone with dementia believes a neighbor has stolen his coffee cup. Rather than reasoning with him (“Your coffee cup hasn’t been stolen; it’s in the bedroom where you left it”), the best thing to do is acknowledge his feelings (“I’d be angry too if someone took something of mine”).
Reasoning does not help. Instead, it creates conflict, because now, in addition to the “fact” that his cup has been stolen, you are calling him a liar, and/or you’re in cahoots with the thief.
Even showing him the so-called stolen cup will not solve the problem. The dementia-afflicted mind will come up with any number of implausible stories to “prove” to you that the coffee cup you’re showing him is a fraud – probably placed there by someone with evil purposes in mind.
It’s so hard not to argue. But don’t. And if you simply cannot stop yourself, at least know in advance that you’re doing so for your own sake, not for the person with dementia; you cannot reason him out of his reality.
Remember: Acknowledge the feeling. Even if the “reality” isn’t real, the feeling is.
P.S. The 36-Hour Day: A Family Guide to Caring for People Who Have Alzheimer Disease, Related Dementias, and Memory Loss (by Nancy L. Mace and Peter V. Rabins) is a very practical book with explanations and ideas about day-to-day living with dementia. You can read it cover to cover or just jump directly to the chapter addressing your pressing concern. It’s been around for a while and has been updated several times.