"Don't scream so pitifully next time! Scaring people to death, got it?" Although Wang Ping didn't have a heart and wouldn't pant heavily, the sudden cry for help during such a tense moment made him quite uncomfortable just from the secretions in his brain. 

"Got it, got it, young man, but you should at least show some respect to your elders, right? Do I have to greet you first?" An old man with grayish-white hair and beard, dirty beyond description, and a face full of age spots and wrinkles, said with a smile, "Forget it, since you saved me from the oil rat den, I wish you a bountiful mushroom harvest."

Wang Ping gave a somewhat wooden smile, which looked almost like a grimace to the old man, "I don't really understand what you're saying, I don't know how to explain, but I can't remember what I used to do, I only know my name is Wang Ping."

Such an explanation of amnesia was rather clumsy, the old man sighed, "Young man, you're quite alert, if you don't want to talk about your past, that's fine, but don't try to deceive an old man."

"Well, I know I can't hide it from you, but I really don't know how to greet someone or anything like that. Honestly, looking at this world, my head is a mess." Wang Ping hurriedly apologized, then remembered that he seemed to have found this paralyzed old man by following his voice, and had struggled to get him out of the ground cave using a bone pickaxe. Afraid that those oil rats would come after them, he supported the old man for several hundred meters before sitting down on the ground. Why was he still feeling embarrassed?

"Taking drugs is one thing, but there's no shame in it. Looks like you've overdosed, your mind's all fuzzy. Don't worry, the old man won't abandon you. At least I'll help you figure out who you are." Seeing that this young man didn't seem deceitful, the old man probably thought he had just overdosed temporarily, and after getting out of the cave, he recovered quickly, now thumping his chest loudly.

"Thank you, what's the old man's name?" Wang Ping decided to act dumb and asked the skinny old man.

"Just call me Old Turtle." The old man proudly announced his name.

"Huh? Old Turtle?" Fortunately, Wang Ping's facial expressions were slow to react, otherwise, he would have burst out laughing. "Why would anyone call themselves Old Turtle?"

"What's so strange about it? I've lived over a hundred years, and I can't even remember my original name. The elders said, 'a thousand-year-old turtle, a ten-thousand-year-old tortoise,' so I call myself Old Turtle." Old Turtle said proudly.

"A hundred years old? No way, you don't look it at all!" Wang Ping couldn't believe that he had randomly run into someone who had lived to be a hundred, let alone someone who still had so much energy.

Seeing that Wang Ping didn't believe him, the old man rolled up his sleeves or, more accurately, untied the animal skin wrapped around his arm, showing Wang Ping something on his arm. It was a series of patterns similar to skin lines, seemingly some kind of tattoo. Wang Ping counted them, ten and a half.

After seeing Wang Ping finish counting, the old man tied the animal skin back around his arm while explaining, "There's no way to keep track of days out here on the wasteland. In our village, we have a custom: when a child is born, they get a small tattoo, and every winter, another mark is added to the arm. After ten years, a complete circle of patterns is formed. Now you know how old I am, right?"

"Wow! How is that possible?" Wang Ping was genuinely surprised; it was unbelievable.

"What's so strange about it? Seems like you really are confused from the drugs. First, you forget basic manners, and now you're surprised by my age. My ancestors were long-lived people; it's not unusual," Old Turtle replied nimbly tying the leather rope around his left wrist.

"I really don't know, could you tell me more?" Wang Ping carefully smiled, knowing that centenarians weren't uncommon in his time due to medical advancements, but he had never seen one as lively as this.

"Alright, but first help me catch those oil rats!" The old man said straightforwardly, "I've been tracking this nest of oil rats for two days. If I wasn't so old, I wouldn't have slipped and been dragged into the hole by that damned female rat."

"How many big rats are there? Are they dangerous?" Wang Ping was puzzled; why would this Old Turtle, who had just escaped from the clutches of the rats, want to go back and risk his life again?

"Are these rats dangerous or not? Forget it, looks like you really don't know. Let me tell you about these rats first," the old man said, noticing that dawn was approaching, deciding to explain about the rats to Wang Ping.

These rats are known as oil rats on the wasteland. Typically, a nest consists of two large ones and dozens of smaller ones. The largest can grow to over a meter in length, and including the tail, they can reach three meters. Their tails are equipped with backward-facing spines, and their bodies secrete oil, which is highly flammable and serves as nourishment for a type of mushroom called the numbing mushroom. These rats, regardless of size, primarily feed on carrion but also eat plant roots and other vegetation. They usually dig a main den underground, and once the mushrooms start growing inside, they begin digging traps around it. When prey falls into these traps, the rats drag them into the pits. As the prey struggles, they inhale the gas emitted by the numbing mushrooms, becoming paralyzed. Though conscious and able to speak, they cannot move and will eventually starve to death, only to be dragged back into the main den and eaten by the rats.

"This, these are rats? Then, how do you catch them?" Wang Ping was somewhat doubtful whether he was still on Earth, how could there be such rats?

"Male and female rats are very protective of their young, they stay in the nest during the day and don't come out. These rats are extremely afraid of light, so if you dig open their main den during the day, they won't run away even after the smell disperses. The parents won't abandon their young and will remain in the nest waiting for you to catch them. However, their nests are very deep, making it hard to dig," Old Turtle answered, "Another method is to use sharpened wooden sticks to poke into the soil traps they dig. At night, jump into the trap, wait for it to hear the sound and wrap its tail around your leg, then drive the sharp stick into the base of its tail. One stab and it's caught, then grab the tail and pull it out."

"Were you trying to use the second method, but acted too slowly and got pulled into the hole?" Wang Ping began to understand what the old man wanted him to do.

"Yes, once in the hole at night, you're dead meat. Take one breath of the numbing mushroom gas, and you'll be paralyzed until now. Fortunately, I can still speak, or I wouldn't know how I died," Old Turtle realized that Wang Ping really knew nothing and continued to explain, "Although oil rats eat rotten meat, as long as you don't mind, the meat of these several-pound rats tastes pretty good. Their fur is waterproof and warm, and the oil can be refined to make torches and lamps, which are quite useful."

"I'm not eating rat meat, and I can't, hehe," Wang Ping chuckled dryly, then thought of a question, "Helping you catch the rats is no problem, but you mentioned the village customs earlier, why hasn't anyone from the village come to help you?"

"Don't mention it! Those beasts of the Eternal Life Sect!" The old man seemed to be reminded of some sad memories and cursed, "I'll tell you later. Wait until it gets light, Old Turtle will show you a new thing buried nearby, very useful for catching rats!"

Before Wang Ping saw Old Turtle's secret weapon, he kept guessing what it could be. Rat oil is highly flammable, so explosives like gunpowder definitely couldn't be used, or a spark might cause the ground to collapse. Could it be the legendary most powerful single-soldier directional neutron blast grenade? While it can produce a neutron beam lethal enough to kill any living thing within a certain direction and range, encountering such a device casually seemed far-fetched.

During the remaining time before dawn, Wang Ping did not waste it. He learned some general etiquette from the old man. According to Old Turtle, longevity came at a cost; his memory could only retain the last forty to fifty years, and things too distant or infrequently recalled would soon fade away. However, important manners on the wasteland were not forgotten, as misusing greetings could be fatal in certain situations.

In short, common etiquette usually requires visitors to greet the host first, though this is not absolute. If the guest is esteemed, the host may also greet first, but regardless of the order, the first greeting is always: "May your mushrooms flourish." There are various explanations for this, and Old Turtle believed that in the past, there were many years when people couldn't find food, leading to widespread famine. Later, someone discovered that planting mushrooms on wood could yield a year-round harvest, ensuring that people wouldn't starve as long as there was wood. Thus, people started wishing each other "May your mushrooms flourish" upon meeting. Over time, this became a greeting, and the response was also significant. It's now difficult to judge someone's origin by appearance alone, and sincere visitors often directly respond to reveal where they come from. Of course, this is not absolute, as those with ill intentions may lie.

"No matter what, those who answer with something related to wood are mostly from the mountains, those who answer with something related to rats are mostly from the wasteland, and those who answer with something related to iron ore are likely from around towns," Old Turtle concluded with a few examples of common responses.

"Town?" Wang Ping finally remembered to ask, "Are there still towns now? Is there still a country?"

"Of course there are towns, but in all my years, I've only seen caravans and such coming from towns, never entered those places myself. I've only seen them from afar. Many tales about towns are just hearsay. The wasteland is vast, and there isn't a real town anywhere. Plus, I heard they don't welcome outsiders, and many towns have peculiar rules," Old Turtle mused for a moment, then hesitantly asked, "Country? It's been a long time since anyone mentioned that word. I don't know if there are countries now. I only know that a place called the world had many countries a long time ago. As for the wasteland, I've never seen anything like a country."

"It seems I'm really unlucky. Not only do I not know what era it is now, but there are no countries anymore," Wang Ping thought to himself, somewhat dejected. The casual chat between the two ended as the first rays of dawn illuminated the wasteland. Old Turtle showed Wang Ping his rat-catching tool with great pride. It was a folding iron shovel, apparently made of stainless steel. According to Old Turtle, finding this shovel was pure luck. A few years ago, he climbed a mountain looking for food and found it among the bones at the bottom of a cliff. It was handy and easy to carry.