Later, Lin Chaoxi thought that if a time travel of more than two months could completely eliminate the ten-year distance, it would be the biggest joke in the world.

When I left the lecture hall, it was already dark. Many buildings in the university town were dim, but some classrooms were exceptionally bright in the night. Through the windows, I could see many students in many classrooms, they were studying hard under the incandescent lights, and the books were piled high on the desks.

Lin Chaoxi didn't look back at the report room or his phone, and went straight home.

When I opened the door, I could smell the faint aroma of cooking.

Lao Lin had already arranged the food in the yard. A chandelier hung from the flower stand, and the grape vines were just the right shade of green, swaying gently in the night breeze.

Seeing the injuries on her body, Lao Lin exclaimed "Wow".

"Are you going to fight?" asked Lao Lin.

"No!" Lin Chaoxi threw his schoolbag and sat down in the rattan chair, "I did something brave and righteous!"

Old Lin shook his head, pointed at her face with his chopsticks, drew a circle, and said regretfully: "This is an unhappy face. You are not happy even though you did something righteous. Lin Zhaoxi, your ideological awareness is not high enough."

"Because it hurts. What if it leaves a scar and no one wants to take care of it in the future?" Lin Chaoxi picked up the chopsticks and pretended to be worried.

"Will anyone want it if it doesn't leave a scar?" Lao Lin asked with a smile.

Sure enough, he is my biological father. Lin Chaoxi stared at Lao Lin and pretended to pick up his phone: "Although I rejected Xiao Liu, if I sincerely apologize, write a 3,000-word self-criticism and recite it carefully, do you think Comrade Xiao Liu will forgive me?"

"No, no, no, don't be impulsive." Lao Lin waved his chopsticks quickly, asking her to put down her phone.

Lin Chaoxi smiled, lowered his head, picked up the bowl, and took two mouthfuls of rice.

The food was already slightly cold when it entered his mouth. It was obvious that Lao Lin had been waiting for him in the yard for quite some time.

She raised her head and looked at her father's smiling face in the night.

"I saved a boy today," she said slowly.

"Is he handsome?" asked Lao Lin.

Lin Chaoxi was choked. What kind of image did she have in Old Lin's heart? "I didn't save him because of his face. I'm not that kind of person."

Lao Lin: "So you saved him because he knew Pei Zhi?"

Lin Zhaoxi: ???

Looking at her shocked and speechless expression, Lao Lin was also stunned.

"Your father is just talking nonsense. Did he win again? Should we go buy sports lottery?" Old Lin said as he was about to stand up. "We need to take a note to buy sports lottery, or we will forget. Five million, five million."

"Stop, stop, stop!" Lin Zhaoxi hurriedly called out to him, "Don't be impulsive. I was just sent to the hospital with him."

"This plot is not good." Old Lin shook his head and began to make up a story, "Next, Pei Zhi went to the hospital and you bumped into each other again. He sent you to get medicine and added your WeChat..."

With a click, Lin Chaoxi's chopsticks fell.

Lao Lin was even more stunned.

After a while, Lao Lin poked his head out and asked quietly: "I guessed it right again. Chaos theory is quite interesting..."

Lin Zhaoxi: "Comrade Lao Lin, what is your pen name on Jinjiang Romance Station? Can you tell me?"

"No, no." Lao Lin waved his hand quickly, "I'm not that kind of person."

Lin Chaoxi felt the ridicule.

After Lao Lin finished speaking, he almost died of laughter: "It's so ridiculous."

Lin Zhaoxi was helpless: "What's even more ridiculous is that after I came back from the hospital, I went to school to attend a lecture on p/np issues, and Pei Zhi was the translator again..."

"What a twist of fate." Lao Lin sighed.

"yes."

After saying "yes", both father and daughter were silent for a while. There were frogs and cicadas chirping outside the yard, but it was quiet inside.

Lin Chaoxi looked at the dim light coming through the glass windows at home and heard Old Lin ask, "How was the lecture?"

This is Lao Lin.

"I could understand it at first, but later I couldn't understand it at all." Lin Zhaoxi answered seriously.

"This is not easy. Pei Zhi has worked very hard." said Lao Lin.

Lin Zhaoxi: “…”

"Is there anything you don't understand?" Lao Lin asked while sitting at the small dining table.

Lin Chaoxi nodded, took out a notebook from the chair next to him, and started asking questions.

“I roughly understand the concept of popular science, but I don’t fully understand the mathematical definition of this problem.”

"Where?"

"Here."

Lin Chaoxi moved her chair and moved next to Lao Lin. She opened her notebook and pointed at the key words with question marks.

"Oh, this is a salesperson's problem. You know this, right?"

Lao Lin's voice was calm and the night was soothing and pleasant. It was just a dinner, but it turned into an academic Q&A session.

As Lin Chaoxi listened, he suddenly raised his head and looked at his father's profile.

He had a little bit of white hair on his temples and looked serious and focused. He was using easy-to-understand language to open the door to the world of mathematics for her little by little.

How long has it been since I had such a moment?

Lin Zhaoxi didn't remember either.

But she is sincerely grateful for the opportunity to go back to the past and make all the long-forgotten wonderful memories clear again.

The night breeze was gentle, and Lao Lin spoke for a long time. Compared with the short popular science lectures given by Professor Howard and Pei Zhi to the public, Lao Lin's way of speaking was even more profound and simple. He spoke with ease, and was more targeted at the content that she did not understand. Every concept and every term was explained by him, gradually stripping off the rough outer layer and becoming clear and understandable.

After Lao Lin's explanation, she could gradually see how far the distance was.

Lin Chaoxi even wondered for a moment whether Old Lin had also been immersed in this issue for a long time, otherwise how could he know it so clearly?

"How do you feel?" Lao Lin asked finally.

"It's still very difficult." Lin Zhaoxi answered sincerely.

"Of course it's difficult." Lao Lin couldn't help but laugh, with wrinkles at the corners of his eyes particularly obvious. "It's the Millennium Puzzle, where does the sense of superiority of mathematicians come from when ordinary people can understand it?"

Lin Zhaoxi: “…”

"Relax a little," said Lao Lin. "Life is long. You can pursue whatever you like. Don't push yourself too hard."

"That's not what you said yesterday?"

"After all, I didn't solve Pei Zhi's problem in an instant yesterday, so I don't have enough confidence." Lao Lin said righteously.

"Ah?" Lin Zhaoxi looked at Lao Lin blankly:

"Don't push yourself too hard. If you can't do it, you still have your father." Lao Lin blinked and kept silent.

Lin Chaoxi pondered over these words and suddenly looked at Lao Lin with wide eyes.

"Comrade Lao Lin, you can't do this!"

Lao Lin was about to take a pen and said, "I'll write the answer for you?"

"This is the sugar-coated bullet of the knowledge world. Take it away and stop tempting me!"

Lin Chaoxi pushed his hand away and turned to take out the schedule from her schoolbag, as well as the materials for today's registration. All the papers were piled on the corner of the table.

"Instead of writing answers for me, why don't you teach me how to learn..."

When she said this, things around her suddenly became quiet. She looked up and saw Lao Lin, his eyes fixed on something on the table.

She felt strange and subconsciously followed his line of sight and saw a phone number.

That was the phone number written in her internship lecture notes: 021-576323xx.

When she looked up again, Lao Lin was looking at her and she was also looking at Lao Lin.

Lin Zhaoxi: "Dad, if you want to ask me how I got this number, you don't have to read such a long message..."

"Ah?" Lao Lin's reaction was very typical.

"Does this phone number look familiar to you?" Lin Chaoxi asked tentatively.

Lao Lin looked at her with a look of deep innocence for a moment, but then became confused, and finally said, "Where did you get this number?"

Lin Chaoxi licked her lips, remembering the story she once told the arrogant version of Old Lin.

"I had a dream last night that I fell into a rabbit hole..."

"Isn't this Alice in Wonderland? Stop fooling us Alzheimer's patients!"

Lin Zhaoxi: “…”

"Caring for your old father starts with the little things."

Lin Zhaoxi: "It was really a dream." She smiled. "In the dream, I was abandoned and grew up in an orphanage. I don't know how you lost me and became cynical. On the day we did the in-person identification, you called this number and I saw it."

"What does cynicism mean?" Lao Lin was very skeptical.

"I know you, I hugged your thigh and called you, but you ignored me. It feels like the whole world owes you a 5 million lottery ticket!"

"Dreams reflect a person's subconscious mind. Tell me how terrible your old father is in your mind!"

Lin Zhaoxi: "Dad, your focus is so off the track. Are you changing the subject because you feel guilty?"

"Why do I feel guilty?"

"Whose phone is this?" she said. "I checked Baidu, but there was no result. It should be a home phone..."

"Comrade Lin Zhaoxi..."

"exist!"

"Your old father has Alzheimer's disease, and he still has to endure your interrogation. He feels very uncomfortable and suffocated." Lao Lin said as he stood up, holding his chest, and left with the bowl of food.

Although Lao Lin was joking, his expression clearly showed that he didn't want to say it.

Lin Chaoxi has asked himself countless times whether he should find out what happened back then.

But looking at Lao Lin's back as he walked into the house, Lin Chaoxi thought, children have their own secrets, and adults have their own secrets. It is everyone's right to keep secrets, so Lin Chaoxi decided to respect him.

She turned around, raised her chopsticks, and prepared to pick up some food, but she found nothing.

"Dad, let's go, just give me back the hot pot bullfrog!"