The fact that a good marriage is dependent on the abandonment of egocentricity is alluded to in the passage immediately preceding the description of the creation of woman (Genesis 2:9,16-18):
And G-d made grow out of the ground
every tree pleasant to sight and good to eat,
and the tree of life in the midst of the garden,
and the tree of knowledge of good and evil….
And G-d commanded Adam, saying:
You may eat from all the trees of the garden,
But do not eat from the tree of knowledge of good and evil,
for on the day on which you eat of it you shall surely die.
And G-d said: It is not good for man to be alone;
I shall make him a helpmate.
Evil takes root in man when he focuses on himself and his own desires rather than on G-d and His desires (or, on a deeper level, when he considers himself independent or separate from G-d). When so oriented, he evaluates all experience only in terms of his own subjective sense of good.
In Kabbalah and Chassidut, it is explained that good tainted by selfishness is represented by the tree of knowledge of good and evil, while true, unadulterated good is represented by the tree of life. By commanding Adam not to eat the fruit of the tree of knowledge of good and evil, G-d was warning him not to mix good and evil by choosing the path of self-centeredness and self-orientation.
Eating the forbidden fruit caused man's psyche to become overtly self-conscious and egocentric. His sensation of good is no longer pure and Divine but a mixture of good and evil; he considers something good only if it is self-gratifying. If this attitude is left unrectified, the evil will eventually swallow up the good, as in Pharaoh's dreams (Genesis 41:1-7); one's appreciation for good–and even belief that anything can truly be good–will evaporate. This in turn will engender a feeling of bitterness toward life as one comes to blame others for life's disappointments and suffering. Having thus placed the cause of his suffering outside his sphere of influence, a person views himself as a helpless victim of circumstance and malevolence.
The two states of consciousness symbolized by the two trees are primarily expressed in the way man relates to woman. In forbidding Adam to eat the fruit of the tree of knowledge of good and evil, G-d was teaching him how to relate to his soon-to-be-created wife: "Do not mix egocentric lust and desire for self-gratification with the experience of true, unadulterated good."
In the entire narrative of creation, the creation of woman is the only creative act described as righting an inferior situation. Furthermore, the previous situation is not described simply as "bad," but as "not good," implying that the preceding state appeared to be good, but really was not. In order to achieve the truly good state, G-d had to create woman.
In this context, "not good" is the incorporation into man's psyche of relative, apparent good. This apparent good is man's existential state of being alone, i.e., egocentric and solely concerned with himself.
A husband with this orientation is feeding on the tree of knowledge of good and evil. Unless he reorients himself to true life and goodness, "on the day that you eat of it you shall surely die," that is, he will eventually say: "I find woman bitterer than death."