Here's an issue many men have a huge difficulty grasping:

Why on earth are women unable to appreciate a man's paternal investment?

Most of them women, once they reach the Wall, are frothing to have a baby. And once they do give birth, instead of becoming a warm and loving creature, appreciative of their family bliss, they become manic harpies, always demanding and never happy.

This behavior goes as far as to overwhelm and wear out most men, even undermining their capacity to provide to their own family. A few years into that procreation event and it's high-season for divorce.

It doesn't make sense, does it?

Why would women have such a behavior that would ultimately undermine the well-being of their own children? Why would they leave their children fatherless?

Now, there is this theory in TRP about the beta-ization process, re-interest in Alpha men after the Epiphany stage etc. These are all valid. But I believe there is a deeper, evolutionary reason for all this. It goes back to the mating pattern of the primates.

Brought down to their very basics, the male sexual strategy is to impregnate, maybe provide for a few months, and re-do. There is such a huge evolutionary benefit for males in that strategy, that spending your life providing for your own children instead of seeking to impregnate other fertile women is essentially only damage control, a desperate measure. I don't think it can be even dubbed a valid male "reproductive strategy".

The human feeling of being "in love", "eros", gives us a great insight into all this: It only lasts one to two years - i.e. just enough for the man to impregnate and maybe provide a little bit.

Have in mind the very crucial point that the first homo-sapiens did not consciously know that sex lead to procreation! - just like other primates. Men didn't know who their children were, in fact they probably didn't even know that they fathered children at all.

Now, imagine human society before institutionalized marriage, i.e. man's obligation to provide for a woman and her children for all his life. You fall in love, this is such a potent feeling, you mate, there is childbirth, the "in love" evaporates, and you fall in love with another women.

"In love", again. That potent feeling we mentioned. With another woman.

Why on earth stick around the first one?

Imagine now being a woman back then. You get impregnated, and you only have a couple of years to milk the man for all he's got, before he runs away to greener pastures.

So, you evolve to be a harpy.

The fool is in love with you, and will try to please you, doing everything in his capacity - and more. Granted, this is a sort-sighted tactic, it can only last a few months before it will explode and he'll say "fuck this" - and leave. But, hey! he'll leave anyway! His evolutionary urge will get him there anyway.

So, yeah, why on earth don't milk him for all he's got for a year or two?

Of course, modern day institutions are different - and have been so since the advent of Agriculture. Paternity is recognized, men are obliged by law to provide for their children (their wife's children, in any case) for 18 years or more. This is all right and correct, in a logical way. Problem is, woman's emotional hardware never evolved to appreciate that. Women, being very close to mother nature, their animalistic origin, emotions rather than logic, etc etc, still operate on the premise that they have to squeeze men dry before they run away. They view their children's father as a product with an imminent expiration date, that they urgently need to take advantage of.

So, what can we men do about it?

First thing to do, understand it. There are many repercussions about fatherhood, our sexual strategy etc, but unless we understand how deeply woman's incapacity to appreciate men's effort runs, all our efforts for the best in relationships, love, etc, will only be remedial.

TL;DR

Woman are fundamentally incapable of appreciating all your parenting efforts. Plan accordingly.