The things he has been saying are hurtful and I am disappointed as I have been caring for him since my mother died. I only know because my brother called to tell me he was concerned that I was not taking care of dad and my sister called to say that my father has said really nasty things about me. My father's behavior is out of character with how he was before my mother died 10 months ago. Is this grief or dementia? He has been somewhat forgetful also.