Unreasonable expectations may also be motivated by a lack of care about the partner especially when there is a personal lack of self-esteem. When bargaining fails, reverting to despair or to anger or attempts at domination or humiliation are signals or indicators of a hurt child. Intensity mirrors the extent of the wound the child experienced. Getting needs met through coercion doesn't work. People change because they want to not because you want them to.
People entering marriage and committed relationships do change some of the things they do.
And all people change and grow as they age. But people rarely change for the better when they are under pressure from someone else even a loved one. Inflicting injury whether physical or emotional, will not get your needs met, but will be more likely to lead to the demise of the passion, joyful connectedness, lost idealization, and falling out of love. Accepting the reality that a power struggle is inevitable, even a deliberate act of nature, can help to develop empathy rather than anger. What your partner is least capable of giving is what they most need to do in order to get over childhood wounds.