They would agree to have Sue, a neighbor, come in when we weren't there. Then they would forget they agreed and they didn't want to have outside help.

Mom wouldn't remember things. She would, say, make cheese sandwiches, only you'd have bread and butter and no cheese. She'd just forget the cheese in cheese sandwiches.

They were angry because you can't reason with people who can't reason. That's an aspect of Alzheimer's we don't always quite get.