Why does Offred think about the verb 'falls'?

Gilead's theocracy believed that if one were kept from knowledge, one would be protected, even from his/her own mistakes. The fall refers to a fall from grace, something that occurred when someone knew more than they needed to resulting in a loss of innocence. Offred sees the fall for what it is, she experienced the change and knows that the fall is not what they're being taught. It is in fact, the exact opposite. Gilead was not a response to the 'fall,' but rather was the fall.