I was originally typing this as a comment reply to this thread, but it turned into an entire post.
/u/projectself was writing about how women re-write history towards the end of a relationship:
Re-writing of history - It doesn't matter that she was sending you love notes and texts a month ago. She has been unhappy for a long time now.
I call this the light-switch effect. And it happens when a woman is no longer attracted to you and is moving on, whether or not she cheated.
It's not that she's discrediting all the past good in the relationship, she actually believes it never existed. Let me expand on that a little, and tie it into what we call Briffault's law.
Women use their emotional state to define reality- we already know this. When a man feels an emotion, he asks, what could have caused this emotion? Is it reasonable and rational? Perhaps it is, or is not, but exploring this line of reasoning is how he determines whether or not his feelings match objective reality. If the facts don't line up, perhaps his reaction was wrong.
When a woman feels an emotion, she uses this as her objective reality. Why would she feel betrayed unless somebody had betrayed her? Why would she feel sad unless somebody or something made her sad?
Therefore the decisions she makes based on her reality may seem like total nonsense to a man (women are crazy, right?), because she has determined her reality based on the only prime truth she knows: her emotional state. If a woman is sad, she tells you "you made me sad." She didn't decide her emotional state, you did. Changing her own emotional state is outside the purview of her control.
So that means the emotional state she is experiencing means that you've done something to create that state, intentionally or not. Since she is sad, you've made her sad. Her objective reality states that you've done something wrong to make her sad. This is where a lot of arguments begin, because the man mistakenly will argue "you've taken what I said the wrong way, of course I didn't mean it that way," and to her, it doesn't matter what is rational or reasonable. She is sad and she wouldn't be sad if there wasn't a reason to be sad. Her sadness defined this reality for her. If you hadn't done something worthy of her being sad about, she simply wouldn't be sad.
So back to the light-switch effect. When you've dated a woman for multiple years, and things start going sour, you experience the revisionist history where she claims to have "never loved you" or that you were "always abusive." Yes, the always/never statements. And what they reflect isn't a reality, rather, they reflect her new reality based on her emotions.
The thought process looks much like this: If true love is permanent and real, and I am not feeling true love for this person, but rather disdain and anger, then I must be feeling this way because of who they are. They make me feel bad, so they cannot be good. And since this person makes me feel bad I could not have loved them, because I would never love somebody who makes me feel bad (the qualities he exhibits now must have been inherent qualities he has always had). So I must have never loved them. The entire relationship must have been a lie. Real true love would be permanent, and this is not permanent, so it was never real true love.
And just like that, her emotional state defines a new reality, where nothing was ever good and everything was based on a lie. Like a light-switch goes from on to off, everything that you two had built disappears into the off position, as though it had never existed.
Many men at this stage try to bargain. "After all we've been through together, how can you throw this away? We can still salvage this!"
And it's a pointless question. What is she throwing away? Absolutely nothing, in her mind. If there was any value in the relationship, she wouldn't feel this way. Therefore there must not have been value in the relationship.
Briffault's law operates around this very principle:
The female, not the male, determines all the conditions of the animal family. Where the female can derive no benefit from association with the male, no such association takes place.
Past benefit provided by the male does not provide for continued or future association.
Any agreement where the male provides a current benefit in return for a promise of future association is null and void as soon as the male has provided the benefit (see corollary 1)
A promise of future benefit has limited influence on current/future association, with the influence inversely proportionate to the length of time until the benefit will be given and directly proportionate to the degree to which the female trusts the male (which is not bloody likely).
Specifically corollary 1- past benefit does not provide for continued or future association. The concepts of past benefit and continued association requires a consistent objective reality where a woman can look at the implicit contracts made in a relationship: We'll love each other forever, we'll make it through thick and thin, I'll give you a place to live and provide for you, and you'll remember these sacrifices I made in the future when the chips are down.
In her mind, when the chips are actually down, her emotional state will define a new reality where past benefit doesn't just not count, but rather it simply doesn't exist at all. If her reality included that your sacrifices and love were genuine and real, she wouldn't feel the way she does. She wouldn't feel betrayed, she wouldn't feel unattracted. But she does feel unattracted to you, so the reality where you provided benefit must not be real. The real reality is that you must have lied, and there was never a true relationship at all.
The light-switch effect.
And make no mistake, even if you're in a good relationship with a good woman, when the chips are down, the light-switch always turns off.