They both give the hard time and have the hard time---at the same time.

I identify with your use of the word mercurial--that's me too. Through most of my life I have thought of myself as a really nice person, I've was challenged by the toddler stage of each of my sons. My husband in his 9th year since Alz diagnosis is now in a stage so very similar to toddlers. But, it's the differences that send me over the edge. Toddlers are teachable and quickly learn the rules of proper behavior. It's a short stage and you know they will grow out of it. Spouses with Alz are going in reverse--you must teach them every day how to brush their teeth, button, zip, and belt, eat, take their pills......you name it. And after you teach them each day you know they will not remember it a moment later. So your use of the word exasperation I also identify with. And I too, have yelled at my husband often this year and this after 51 peaceful years of marriage with only one or two heated arguments. Now in year 52, I find myself angry often and I too ask myself why. I think it is the underlying grief of losing the once "genius", gifted, man you married. My husband is still handsome and more fit than he has ever been because now he can't go out and eat fast food for lunch every day😁, but he rarely realizes I am his wife and is as likely to hug a woman stranger in a store as he is to hug me. So, that's hard emotionally, but like me you probably have little or no time to reflect or process these things. So, when a behavior is particularly bizarre or repetitive we are at some level horrified that this is happening to our beloved and there is no one else nearby for us to yell at in the moment so we yell at them. If possible I have found it helps to step out of the room, take a breath, remember that you love this person with all your heart and go back in --say you are sorry, reassure them that you love them and will care for them as long as you are able and if they will let you, give them a hug. They may not understand the words or the hug, or the tears, but your tone of voice will mean love to them and it matters to your heart and your well-being. Know that you are not alone. God sees and knows every dark moment and he is not condemning you, but there to lift you back up, set you on your feet and fill you with enough love for another day. Alz. is a disease. None of its peculiarities can be controlled by the person experiencing it. Caregiving requires intentional acts of love and care in spite of what we see and feel and experience. Find help in friends and family and in faith. Take moments for yourself wherever you can find them in your day. Cherish every day you have with your loved one as they are now and find joy in each moment you catch a glimpse of the person they once were.

Helen5
Oh, I do know where you are. We are 8 years in and the repeats have been accelerating the last month. Some days I am good with it. Sometimes I snap and the feel stupid. The disease so scrambled everything. I don't think they would even know at this stage whether they meant the question or not. I know you are aware that the speed of decline is so variable. I understand your fear of what's coming. There was never better advice than to take one day at a time. I am not that good at really considering this even though it makes perfect sense. My husband tonight has asked if he can get me anything at least 15 times. He absolutely has no recall of this. At dinner he told me over and over that he loved the ice tea.
It's scary, it stinks, I hate it.
You are so overstretched that your nerves are probably more easily frayed. Hugs

When you experience these exasperating behaviors, just remind yourself his mind is broken. He cannot help it. Do not expect logical behavior from a broken mind. You will only frustrate yourself. Remind yourself, "He is not giving you a hard time, he is having a hard time."

I would first contact the place so they know when you are coming. Call when you get there. Someone should be able to come out an help you get her in.