One of the most important things to remember about this story is that you only have one character's perspective, and this will always, in any story, limit the reader's knowledge about events. Therefore, every detail needs to be considered. With regards to the narrator's condition and her husband's attitude, think about how this house is described, every detail, in every room. The narrator does not become mad or insane as she stays there; she enters the "sanitorium house" already unstable. It is her perception of her husband's actions you are reading.

The husband, John, in the "Yellow Wallpaper" doesn't see the seriousness of his wife's deterioration because following along with the beliefs of that time, he thinks its impossible that a woman could have a mental illness. With so little to do and virtually no stimulation, the narrators mood varies. She realizes that she's starting to see shapes in the yellow wallpaper. She becomes completly obsessed with the wallpaper, and even beleives that her husband is trying to see the shapes before she can. Finally, she succumbs completely to her insanity.