Library

Outside the Po On Road Municipal Services Building in Sham Shui Po, a yellow taxi slowly pulled into the parking area.

"There we are. One hundred and ten dollars. This is the nearest large library to where we were earlier. I heard it only opened a few years ago."

In the driver's seat, a short, stout middle-aged cabbie twisted around, pointed at the building outside the window, and spoke to Yang Chu in the back seat.

"Thanks!"

Yang Chu glanced at the building outside, pulled a hundred-dollar bill and a ten-dollar Hong Kong bill from his wallet, handed them over, then opened the door and stepped out of the taxi.

He entered the Municipal Building, went up to the second floor, and arrived at his destination: the Po On Road Public Library in Sham Shui Po.

Yang Chu intended to thoroughly look through the books, hoping to find a solution somewhere among them.

He had not chosen to seek help from doctors or other professionals. Hong Kong Island was a capitalist society, and with less than a thousand Hong Kong dollars left in his pocket, he did not even qualify to make an appointment at high-end clinics or with specialist medical staff.

Taking a step back, even if he could contact a suitable institution or professional, setting aside whether they could solve his sleeping problem, he would certainly become a research subject and experimental object in the short term.

Of course, when life and death were at stake, there was nothing that could not be compromised.

But unless he truly had nowhere else to turn, Yang Chu would not lightly let others take control of his destiny.

He did not even know why he thought that way—

Many parts of his memories from his previous life had already faded, and even the course of that life had become blurred.

Fortunately, his logic of thought and behavior, along with much of the knowledge he had once learned, remained intact.

When facing the problems he encountered, his conscious mind could make judgments and choices based on the current situation.

As for whether those choices were correct, effective, or capable of solving his current problems, there was no way to think any further.

Besides, these somewhat chaotic thoughts had only been fleeting notions that flashed through Yang Chu's mind while he sat quietly in the back of the taxi earlier.

The Po On Road Public Library was bright, clean, and pleasantly maintained.

The library did not seem particularly large. Four or five employees wearing badges on their chests were working inside.

As soon as Yang Chu entered, his gaze swiftly swept over the various sections of the bookshelves, and he quickly found the biology and medicine area.

There were not particularly many books, perhaps enough to fill four long rows of shelves. The shelves held both new and old volumes, and it was obvious that aside from purchased books, some had likely been donated by members of the public.

Most of the books were in traditional Chinese, with one or two simplified Chinese editions mixed in. A large portion was in English, but Yang Chu did not find that particularly difficult either.

Yang Chu rapidly scanned the rows of shelves, soon stopping before one and pulling out a book.

Its title was The Most Familiar Stranger, with the subtitle Journey of Self-Cognition and Potential Discovery.

Yang Chu roughly skimmed the table of contents and hurriedly flipped through a few pages. It seemed worth reading, so he casually placed it on the shelf beside him and continued looking for other books.

He pulled out two more books, Efficient Rest Method and Condensed Sleep Method. After glancing through their contents, he felt they might contain something he needed, so he placed them on the shelf divider in front of him and continued searching.

"Can't sleep?"

Just as Yang Chu carefully selected books, a gentle voice suddenly sounded beside him.

Yang Chu turned and saw a handsome young man wearing earphones, pushing a small cart piled with books past him.

He appeared to be a library employee.

"Yes. My mind won't quiet down, so I can't fall asleep," Yang Chu casually replied.

"I often can't sleep at night either."

A shy, gentle smile rested on the handsome young man's face. As he placed several books onto the nearby shelf, he said, "If you want to try sleeping better, you can take a look at this one—"

As he spoke, the handsome young man handed an old book to Yang Chu.

Yang Chu accepted it and looked at the title, Why We Sleep. It appeared to be what he needed, so he gave a slight nod. "Thank you."

"You're welcome!"

The handsome young man smiled, then pushed his cart toward another section of shelves.

Yang Chu casually glanced at the books on the young man's cart. Several volumes on top caught his eye: Why We Are Born Here, How to Win Friends and Influence People, and Personality Test.

After the handsome young man left, Yang Chu did not pay much attention to him and continued browsing through the rows of shelves.

He did not begin reading every book as soon as he picked it up. Instead, he kept searching the shelves for books he wanted and placing them before him.

His body was still standing and walking around. Aside from controlling the body's major internal systems, his conscious mind also had to control the motor system. Without his subconscious controlling his body, if he became even slightly absorbed in reading, he would not remain standing—he would suddenly collapse.

If he wanted to read for a longer period, he needed to reduce his conscious mind's investment in other matters as much as possible.

Save Your Sleep, Awakening the Sleeping Brain, Efficient Brain Working Method, The Second Brain, Brain Repair Technique, Consciousness Explained, Brain Nerve Atlas, Introduction to Brain Science...

Yang Chu found more than a dozen new and old books from the shelves in succession. As long as he felt they might be useful or could open up a new line of thought, he kept them.

Then he carried the large stack of books to a reading seat not far from the shelves.

One person carrying dozens of books before sitting down naturally drew the attention of quite a few people nearby.

But Yang Chu ignored their strange looks. After sitting down and adjusting his posture, he began flipping through the books.

The first thing Yang Chu wanted to understand was why people needed sleep.

He seemed to have fragments of memories concerning the matter, but they were not clear enough, and much of it seemed to have been forgotten.

Moreover, those memories focused not on why people slept, but on the many harmful effects of not sleeping, insufficient sleep, the dangers of staying up late, and so on.

A muddled head, physical and mental exhaustion, an inability to concentrate, poor memory, a blank mind when thinking, slower reactions when dealing with matters, difficulty controlling emotions, greater susceptibility to illness and cancer, faster aging, and a general feeling of discomfort throughout the body.

Yang Chu understood the various severe consequences of sleep deprivation, but none of them were the answer he wanted.

After opening several books, Yang Chu gradually found a few explanations.

Or rather, speculations and hypotheses.

The first explanation was that sleep existed to conserve energy.

At the beginning of animal evolution, food was scarce. Sleep lowered the basal metabolic rate, allowing energy to be conserved and restoring energy lost during the day, much like certain animals needed hibernation.

But this explanation now seemed inaccurate. As evolution progressed, energy intake was no longer a problem for humans.

If sleep existed to conserve energy, then people would not need sleep as long as they replenished enough energy.

Therefore, sleep had to have other meanings beyond conserving energy.

The second explanation was that sleep existed for memory.

Sleep aided the repair of neural tissue and had a certain protective and consolidating effect on memory.

This explanation made some sense and was acceptable, but it still did not seem sufficient.

The third was that sleep efficiently cleared metabolic waste from the brain, restoring vitality.

Most metabolic products in the human brain were discharged by brain cells into the gaps between cells, into the interstitial fluid. Another secreted fluid, cerebrospinal fluid, supplied part of the brain's nutrients and removed metabolic waste. Cerebrospinal fluid flowed into the brain along the spaces around the arteries, exchanged with the interstitial fluid of brain cells, carried metabolic waste from that fluid to the spaces around the veins, and was then discharged from the brain.

During sleep, the gaps between cells in the brain were larger than when awake. This meant cerebrospinal fluid could more easily enter the brain and exchange with interstitial fluid during sleep. Sleep might prevent toxic metabolic products from accumulating and damaging brain cells.

Sleeping was like washing the brain with cerebrospinal fluid, clearing away accumulated metabolic waste. The function of sleep could truly be called "detoxification."

Yang Chu felt this explanation had some merit.

It might not be complete, but this was likely one function of sleep.

There were also explanations related to immunity. Sleep produced a specific secretory protein with antibacterial properties.

People often felt tired and drowsy while sick, but the increased need for sleep during illness actually came from signal molecules released by the immune and nervous systems, rather than from the infectious agents themselves.

There were other theories as well, such as sleep originally existing to fulfill a primitive function at the beginning of evolution. As for what that primitive function was, there was no consensus. Later, over the course of evolution, sleep gradually acquired more functions.

Sleep existed to improve brain function. Sleep was related to Earth's day-night cycle. Sleeping at night was a way to avoid natural enemies, and so on.

Among all those books, Yang Chu did not find a definite and complete answer.

He did not know whether the library's collection was too limited, or whether humanity's understanding of itself and living organisms simply had not yet reached that answer.

But Yang Chu felt he had already gained something.

And among the pile of books, Yang Chu found several more ideas he found rather interesting.

One was that people did not sleep at all; "awakening" was what they needed to do.

Most lower life forms had neither sleep nor awakening, remaining in states of low perception and low drive for long periods.

For example, all plants, bacteria, viruses, plankton, and even insects. Their numbers far exceeded the combined total of humanity and all animals. Day after day, they moved mechanically and had never awakened. Yet humans had awakened from among lower life forms, gained intelligence, and gained the initiative to control their own lives.

Yang Chu also learned a great deal from these books that he had never known before—

Among mammals and birds, sleep could be divided into two major stages by analyzing eye movements during sleep—Rapid Eye Movement Sleep and Non-Rapid Eye Movement Sleep.

Rapid Eye Movement Sleep was characterized by rapid eye movements, as well as high-frequency, low-amplitude brain waves and reduced muscle activity. Most dreams occurred during this stage.

Non-Rapid Eye Movement Sleep accounted for roughly 75 to 80 percent of an adult's sleep. Dreams were relatively rare during Non-Rapid Eye Movement Sleep. It included four stages: stages one and two were light sleep, while stages three and four were deep sleep. Each stage possessed different characteristics.

Many animals also slept less than humans. Elephants, for instance, only needed two hours of sleep a day.

Some marine mammals, such as whales and dolphins, did not even need their entire brains to sleep. Their left and right brains could rest in turns, ensuring that half their brain was always awake to handle daily tasks. Some small animals barely slept at all to avoid being caught by predators.

Aside from these books about sleep, Yang Chu found something worth trying in several books concerning the "subconscious."

Cultivating a subconscious that he himself could control.

For example, if an ordinary person suddenly saw something flying toward them or faced a frontal attack, they would instinctively close their eyes.

But a trained boxer or other combat athlete had completely mastered that subconscious instinct through long-term training. When facing an attack, they would not close their eyes. Instead, they would clearly see the attack's trajectory and make their body evade accordingly.

"So? You've been sitting here nearly the whole day. Did you find a way to solve your sleeping problem?"

The gentle voice sounded beside his ear again.

Yang Chu looked up and saw the handsome young library employee standing beside the table, looking at him.

Only then did he realize that it was dark outside. It was already evening.

Aside from the handsome young man before him, everyone else in the library had long since left.

"I've gained something, I suppose. But I won't know for sure until I try it."

Yang Chu also understood why the young man had come over. The library was probably preparing to close. He had gained quite a lot that afternoon. For some reason, he had not only skimmed through every book he had selected, but understood seventy or eighty percent of them.

He closed the book and stood up from the table.

But perhaps because he had been sitting for too long, although he had kept his heart beating and blood circulating, the blood flow in his lower limbs had still become somewhat sluggish. As soon as he stood, he involuntarily tilted and fell to the side.

"Careful!"

The handsome young man reacted quickly and caught Yang Chu. Smiling, he said, "I noticed you hadn't moved at all while sitting here. You should get up and move around a little..."

"Thanks, I'm fine!"

Yang Chu slightly increased his heartbeat, speeding up the circulation of blood through his body. In just over ten seconds, the numbness in his lower body had dissipated, and he no longer needed support.

"You recovered quickly!"

The handsome young man watched Yang Chu recover in such a short time, a trace of surprise flashing across his face.

"I was just sitting for too long."

Yang Chu smiled, then asked the handsome young man before him, "By the way, where's the restroom?"

As he spoke, Yang Chu glanced at the rectangular badge on the handsome young man's chest. It was an employee ID, with several English letters written on it—XUXI.

"My name is Xu Xi."

Noticing Yang Chu's gaze, the handsome young man maintained his slightly shy smile and pointed toward the other side of the library. "Just turn that corner and you'll find it."