I know it is hard to imagine, but sometimes there are positive personality changes that happen with dementia. I knew a man who was a difficult, abusive alcoholic who after he developed dementia in his 80s and reverted to a time in his life before he drank. He became gentle and loving, much to the surprise of his wife and family. In this NYT article Steve Knopper
shares the personal story of his mother's changes with Alzheimer's disease.