When I am home alone, I can always know who is coming in just by their scent For example, when my mother gets home from work I can almost always know she coming in through the door. Since my mother works in a factory and works around metal and oil, she carry's the scent of oil and metal after work. So when I hear the door open I know its her before I even see her. I have not realized this before, I just always unconsciously know its her. But now that I've read the book, I can understand the importance of smell.