In Alain de Botton's talk,Why You Will Marry The Wrong Person, Alain describes the following:
Rage is just shattered hopes. And so if we are to get a little less angry and a little less sad about relationships, we have to diminish some of our hopes.
Success is finding a person who's good enough, not someone who's perfect.
In Some Thoughts about Relationships, Colin Wright sets out a few dozen 'policies' to set out terms for healthy relationships.
The most important policy: awknowledge cause and effect, the possibility of iterative improvement, and the potential to solve problems.
Being irrational tends more towards making up storylines, going through unnecessary struggle, and hoping that trying hard enough will get you to where you want to be.