"He's always been too lazy to think for himself"!
That's one of the things my DM said to me over the two or three years I spent trying to convince her that my DF needed to be assessed for dementia. He does have dementia - now diagnosed and getting progressively worse.
Those of you with the husbands or partners who are also "too lazy to think for themselves" might want to ask them what's so great about living in such a way that their habitual laziness of thought is indistinguishable from dementia or cognitive impairment!
My DF is in his mid 80s now, and to be very honest, in many ways his dementia hasn't made much difference, so I can very much understand why his habits of many years made it so much easier for my DM to deny the inevitable.
Whenever he drove anywhere, with my DM in the passenger seat, he would ask her for directions - no matter how well he knew the route.
He didn't bother to remember his two daughters' names - we were interchangeable to him. I react to hearing my sister's name as much as to hearing my own.
Home life was a constant refrain from him of:
"Where's my .... ?"
"When is xxx starting/finishing/happening?"
"No one told me about .... (something he'd been told about repeatedly)"
And yet, he knew fine well the wheres and whens of things that mattered to him!