I'd think 'In a relationship we should never have his kind of fight.' Then instead of figuring out how to make it work I looked for a way to get out of it. The truth is you shouldn't be married if your that kind of person.
The Polar Express is about faith and the power of imagination to sustain faith. It's also about the desire to reside in a world where magic can happen the kind of world we all believed in as children but one that disappears as we grow older.