What may be most important here is asking yourself why we all assume that she doesn’t mean it. While it’s fair to say that we often dismiss our own feelings with a wave of the hand and a quick “I’m fine,” the idea of a woman using that little phrase as a catch-all for resentments that she expects you to pry out of her slowly over the course of the evening has become a trope all its own. When we hear her utter those words, we roll our eyes and roll up our sleeves and immediately set to deciphering what it is that she really wants to say. The idea that she actually is fine, or that her problems could stem from anywhere outside of her relationship, never seems to cross our minds.
When a woman says that she is fine, that nothing is wrong, she is doing something that she has always been taught was the right move. She is being chaste with her emotions, playing close to the chest, and not coming across as that hysterical girlfriend that she always knew she could distinguish herself from to earn the pat on the head and the compliment of “not being like those other crazy bitches.” For her to say that she is fine is often a generous act, one that is intended to take the burden of having to decode her problems or even deal with them head-on and place it back on herself. She will either work out her problems internally, or won’t acknowledge them at all.
There are endless articles, books, interviews and essays dedicated to explaining the complex inner workings of the female mind in a committed relationship. You would think that we were a monolithic hive, moving from romance to romance with the efficiency and consistency of a Big Mac purchased in a foreign country. We all believe that we are going to find some secret decoder ring which will allow us to understand these mysterious words, and skip out that nasty middle business of actually having to find out “what is wrong,” even if it’s the question we initially asked. Once we get past the essential realization that she has been socialized to downplay whatever it is that is upsetting her, there are several possibilities as to what could actually be on her mind that lead her to reply with “I’m fine.”
She could actually be fine. There is often no subtext to this response, it’s just the most simple, efficient way to get across her sense of complacent stasis. And it is possible that the prospect of an arduous, drawn-out conversation about the hidden problems is as exhausting to her as it is to you. She is not playing a game of cat-and-mouse, she’s just tired and doesn’t feel like explaining herself any further.
She could have something on her mind that she feels afraid of saying, for fear of seeming accusatory or needy. Sometimes she might really feel uncomfortable about something that’s happening in the relationship, but doesn’t want to immediately come out with her grievances, as that behavior is generally frowned upon in women. (And she likely doesn’t want to hurt your feelings with what you’ll perceive to be an attack.) It is quite possible that the conversation that follows — if it comes from a place of genuine concern and non-judgment on both parts — is a very necessary, natural thing that is highly preferable to slapping someone else emotionally with a heavy-handed complaint right off the bat. We often forget that these conversations (that we are so quick to label as some kind of translation process) are a very healthy part of any relationship with meaning that attempts to scratch beneath the superficial.
She could be upset about things that have nothing to do with you. The truth is that there are some things we can’t always talk about. There may be problems in life that we do not yet fully understand, that are deeply personal, or which involve the privacy of others. Sometimes she doesn’t want to talk about it, or doesn’t think that would be appropriate, and that is fine. If someone is letting you know gently that they are not interested in discussing something, and reinforce that if you pry again, that may be all there is to it. Yes, she may still be unhappy, but no, you cannot do anything about that right now. And that doesn’t mean that it’s anyone’s fault.
She could be a complex human being that isn’t meant to be held up next to an emotional Rosetta Stone. While we are always going to be tempted to figure out the meanings of the things our loved ones will say in life, there is something very strange about insisting that a woman is universally speaking in tongues when it comes to conveying how she feels. Yes, she has been conditioned to hold back much of what she is hurt by, but these are all walls which we can eventually pull down if we treat one another with kindness and patience. The real question, it seems, is not “What does she mean by ‘I’m fine?'” Rather, it should be “Why do I feel that I can’t trust the answer of someone that I love, and why do I feel that she is intentionally trying to obfuscate her emotions?” But that question is more complex, and may even require us to look inward for a moment, so it’s probably best to pick up another How-To book on figuring out your annoying girlfriend. 
