You gave us your "thought for today". There is no logic, rhyme or reason for a PWD's change in behaviours and/or character, words, etc as it wholly, in my humble opinion, depends on which message pathways in the brain are damaged or blocked by the disease - and this may be different for every sufferer.
I feel for you in your OH's position and behaviours. Whilst my OH has changed from the person she once was, she is still polite and swears v little. She's past or mostly past being able to have a proper conversation, but can be v vociferous in sounds and noises. She hates the carers having to roll her, clean her, etc and resists physically by gripping the sides of the bed v strongly, calls them the worst thing she can think of - which is "horrible", but once they've finished and tidy up her blankets she thanks them profusely!
She still wakes up with a smile when I kiss her cheek. One of us remembers the good times that we had and all that we've been through. We've only been together for 56 years, so who knows what the future holds, but after 7 years of full time caring I know it isn't going to be good!
Best wishes
