Several examples of Mildred's closed-mindedness appear when Montag considers quitting his job as a fireman. The night before, he had helped burn not only books but the old woman who owned them. His conscience is tormenting him, and so he thinks of resigning from the fire department. Mildred is shocked:
"You want to give up everything? After all these years of working, because, one night, some woman and her books--"
"You should have seen her, Millie!"
"She's nothing to me; she shouldn't have had books. It was her responsibility, she should have thought of that. I hate her. She's got you going and next thing you know we'll be out, no house, no job, nothing."
"You weren't there, you didn't see," he said. "There must be something in books, things we can't imagine, to make a woman stay in a burning house; there must be something there. You don't stay for nothing."
"She was simple-minded."
"She was as rational as you and I, more so perhaps, and we burned her."
"That's water under the bridge."
If anyone seems simple-minded in this novel, it is Mildred herself.