Ryzel agreed with Lyre, so he can't help but recall history.
Thousands of years ago, before the era of exploration, the technological advancement of humans was just beginning.
The concept of living on different planets was still considered an unrealistic fantasy, which is already a reality in the current interstellar era.
At that time, people were only classified into two sexes: male and female. They don't have sentinels and guides.
That is why, thousands of years ago, people could marry whoever and whenever they wanted without too many restrictions, as long as both parties were willing.
In the era of exploration, human technological advancement in space technology improved, allowing humans to finally venture to outer space and start expanding their territory in the wide universe.
Initially, no problem was found; the human body was adapting well to the unfamiliar environment.
Then, they found out that the number of newborn females was dwindling, but because the ratio was still within an acceptable range, it was not considered a huge problem.
What became a huge crisis for humans was the sudden invasion of the Zergs.
The Zergs looked like insects, but their sizes were several meters bigger, and they ate whatever they came into contact with as long as they had energy.
They can freely traverse in outer space without other support, unlike humans.
When the Zergs first appeared, humanity couldn't even fight back and lost a lot of territory and fifty percent (50%) of the population.
For a hundred years, humanity kept fighting the Zergs, but the result wasn't favorable.
They invented mechas for people to have a chance to fight the Zergs, but humanity couldn't properly exert the power of mechas.
Technology keeps advancing to keep up with warfare, but humanity still can't gain a lot of advantages for them to win.
It wasn't until the appearance of humans with extraordinary strength that the situation for humans changed. They were the sentinels.
Humans rejoiced because the sentinels were extremely strong in combat; they could properly exert the power of mechas, which led them to win.
The joy was short-lived because the sentinels weren't just strong in combat; their senses were also very strong, which led them to have a mania as soon as they reached their limit.
The manic episodes of sentinels caused a lot of losses every time, but because they were the strongest fighters on the battlefield, they were still fighting on the frontlines even though they knew they would die afterward.
The strongest sentinel recorded in history at that time only stayed on the frontlines for seven (7) years before sacrificing his life on the battlefield.
Before the guides were discovered, it was like sending a suicide squad every time they sent the sentinels to the battlefield.
The first discovery of guides was when a sentinel who was about to have a manic episode was soothed by his wife.
Guides are people who don't have strong physiques but have strong mental strength that can soothe the sentinels.
With the discovery of guides, the results in war were noticeably better because of their support.
But a lot of problems still arose because the number of guides was not proportional to the number of sentinels.
With the passage of time, a lot of laws and research were made to alleviate the situation.
In the current interstellar era, the population of normal people is about seventy percent (70%), twenty-five percent (25%) sentinels, and five percent (5%) guides.
The number of guides was still too small, which is why the law that states that guides need to be married at the age of twenty was still followed.
Ryzel's recollection was interrupted when he heard Lyre's voice.
"Well, anyway, we are still considered fortunate compared to our predecessors. They were married even earlier than us."
When guides were first discovered, they were subjected to a lot of injustice.
Because of their small number, in the name of protection, their freedom was compromised.
It wasn't until some guides led a revolution. They controlled their usually mild mental power and quantum beast to cause problems and escape.
After escaping and seeing the world, the guides showed up on the battlefield and sacrificed themselves, curing the sentinels and dying on the battlefield.
They showed their resolve not to be imprisoned again by dying on the battlefield.
It was known as the Rose tragedy, as thousands of guides spent all their mental power and died on the battlefield.
After the Rose tragedy, a lot of laws sprung up to protect the rights of the guides.
But the federal marriage law for guides and sentinels was never abolished. It was only revised twice.
The union of a guide and a sentinel has a higher chance of giving birth to high-level sentinels and guides, which is why the law was made.
At first, it stated that guides who reach the age of sixteen should be married; afterward, the age was changed to eighteen, and in today's generation, guides should be married as soon as they reach the age of twenty.
"Yeah, we are still more fortunate than our predecessors," Ryzel agreed to Lyre's statement.