But yeah, I agree with you. Such aflictions of the mind are much more miserable for the ones close by than the person himself.
I had a great aunt who suffered from altheimers when I was young. She would tell weird tales and be contented to smile at invisible conversations and such as she just stared out the window. It was sad, odd and at times unsettling to us oberservers, but to she, it did indeed seem like a sort of personal bliss. To me as a child, she did seem happy and contented with what she had lost in reality.