It isn't personal, and it is really important that you don't think it is.
It is the illness and they really are overwhelmed by it.   We were accused
of things, and my mother in law had all sorts of imaginings.  At one
difficult moment I thought she might even hit me.   I called my husband into
the room and just calmly let him take over at that time.   She forgot it
within minutes.   Letting it go is paramount.  They let it go because they
can't remember, you need to let it go because you choose to.

Caring for an alzheimer patient is a difficult thing simply because they
can't remember anything and you need to be constantly diligent.  But most of
all you need to realize they can't help it, and nothing is intentional.

Did you know that the brain of an alzheimer patient actually shrinks to half
its normal size and weight?   That is a fact.   So if you see strange
behavior, tell yourself that this person is only operating with a small part
of what their normal brain power should be.   I read an article about that.
I would often say to myself "she is operating with a half a brain"...  and
strangely enough it helped.