Not everyone can see eye to eye but we can at least try to get along. With Ruthie and Bill; Bill wants to argue and Ruthie does not. They find a way to get along in this long car ride with Bill preoccupied with figuring Ruthie out and Ruthie seeing strange things and voicing them out loud. Each has their own outlet for dealing with the situation at hand and though they are not the same ways, they come together in the end.
Bill has preconceptions about women. He compares Ruthie to East Coast women who argue with him all the time. Bill seems offset by the fact that Ruthie does not behave the way he is used to. Bill's alien feelings about Ruthie change by the end of the story.
Ruthie and Bill seem to tolerate each other for the most part. They share the burden of gas money and later take turns driving. They at least know how to coexist, but are intellectually incompatible. During their road trip, Ruthie describes the things she sees to Bill, which at first seem normal. She sees cows, then flowers and a bird, her visions then become increasingly bizarre. She sees things like Bigfoot, a white buffalo, and a UFO, then finally “A handsome genius in the person of Bill himself.”
She seems to be a simple person. Either she genuinely sees these visions because she is an imaginative and eccentric person or she feeds Bill little doses of craziness to get him to stop arguing with her. Bill is so busy trying to analyze her visions that he forgets about arguing.
Regardless of why, Bill surrenders to Ruthie's last vision. When she sees “A handsome genius in the person of Bill himself,” Bill decides to “let it ride.” Obviously Bill has changed his opinion about Ruthie; he no longer tries to force her into his mold of the way women should be.