Marriage

Marriage.

That dream within a dweam.

Origin of the three ages of Women and Men

In the world of Athena Minerva, (due to a certain mutation happening among the early mammals,) during intercourse males transmit to their mate antibodies to every disease they have survived. This helped many mammals continue to reproduce and survive during inevitable times of famine, and reduced the calamity of many pestilences.
Around 1811 B.C. the concept of Natural Sexual Law (NSL) was recorded as a religious belief, using a fairly scientific foundation. It was based largely on objective measurements of life expectancy related to certain behaviors. Specifically NSL was the belief that the Creator of the universe included this quirk in mammals intending for male human youths to travel far and wide, picking up exotic bacteria and viruses, and the survivors who develop antibodies were obviously intended to deliver their seed to many people to inoculate the masses. Correspondingly, female youths should have their pick of young males, particularly those who have traveled from afar.
And just as clearly, this Loving God built men to grow less virile when they reach "a certain age" of maturity at which time He intends for them (like many mammals) to mate for life with the women who select them and provide a stable household to raise intelligent, competent, and powerful children.
This belief then divided the human lifespan into three important phases:

1. Childhood, where parents decide when to switch from pure nurture, (protecting the child from any harm or discomfort,) to a blend of nurturing with challenges to grow the child from innocence (and poor judgement) to experience and adulthood.
2. Age of Promiscuity, where the young adults must set out to make their own way in the world and face challenges solo "without training wheels". Here is where the heartbreaks happen.
3. Age of Cultivation, where adults take all they learned from the highs and lows of life and set out to teach the next generation to be better.

The age of the end of childhood increases over the generations (from 13 years of age to as high as 21) as the average life expectancy increases, but it is subject to little debate.
In contrast, exactly when that age is that males and females should give up promiscuity and settle down is fiercely debated until the end of time.

The Coming-of-Age Traditions

The end of childhood and beginning of adulthood (and the promiscuous phase) includes a public ritual in many societies. They are extremely tailored to the specific values of each society. Many such rituals seem less intent on telling the child that she or he is now to put away childish activities and begin adult activities and seem more intent on advertising to the neighbors that this person is now eligible for adult activities.
Marriage, on the other hand, is quite similar in all cultures across the globe and does not change much as technology evolves. The adults to be married come before an assembly of their contemporary society (mostly friends and relatives) and state their intentions and vow to each other to build a stable reliable home life together. A representative of law and order introduces them to the crowd, allows them to make their commitments, and announces that whatever ruling or governing body is in control fully authorizes and approves of their commitment. It also advertises to the society that these people are "out of the rat race" romantically speaking. Marriage is the Coming-of-Age ceremony that announces the entry the the third (and final) phase of life.