[music] It was 3:00 a.m. at a house not far from here. Susie woke up suddenly feeling dazed and confused. The place looked strange. She couldn't tell where she was and she started feeling anxious. Then this man appeared. He didn't look familiar and he started approaching her. Now anxiety gave way to despair. Wait, wait, she cried. Where am I? And who are you? So the man grabbed her arm and told her, "Easy now. You're home and I'm your son, Mom. " Susi is one of 40 million people living with Alzheimer's deme ...