We lose our rose-colored glasses as we get to truly know our partner, and we decide what this or that action or those words mean, and we come to believe it. And then we act based on our beliefs which are usually not discussed with our beloved in an explicit manner and interactions escalate; the misunderstandings grow in quantity and in magnitude.
I am not promoting being logical as the end-all, be-all, either. Emotion is critical because it drives us (whether we're paying attention or not). However, if we can let emotions (limbic brain) be road signs alerting us to things that need attention, and then use thought (cortical brain), kindness, and compassion to address one another and issues, we're into the best of all (brain) worlds now!
Many of our beliefs come from our family growing up, the education and culture we're a part of. Our beloved came from another family, school, and perhaps even culture or geographic location. So of course s/he sees things differently.
I don't expect us to have rose-colored glasses throughout our entire relationship, but I am a proponent of clear glasses that allow us to see and know ourselves, accepting our best, good, good-enough, and less than desirable traits (which we can choose to work on). Then we are able to see our partner clearly, too, and make space for human behavior.
So let's challenge ourselves in our beliefs about ourselves, our partner and relationship, and see what we think, while allowing emotions to inform us.