My dad was like that with my mom. She had Alzheimer's and he cared for her at home till he could not longer manage it. They went to live at a senior home, and she had to live in the Alzheimer's unit, and he had an apartment down the hall. He sat with her EVERY MINUTE OF EVERY DAY that he was allowed in the unit, for 3 years until she died. She couldn't carry on a conversation, or even enjoy things around her, but he treated her with love and respect as if she was still ' all there'. I always knew he loved her, but until those days, I never realized just how much.