Detailed analysis and discussion to clarify vague ideas

After leaving Liu Che, Xue Jiuyue contacted one of his classmates and asked in detail what medicine was needed for the sprain. He also sent the photos he had just taken so that his classmate could see if anything else was missing.

Soon the other party replied, "It's all ready now. Apart from resting, nothing else is needed."

Xue Jiuyue was still worried and planned to navigate to the nearest pharmacy to ask again.

The distance wasn't far, but the moment the navigation system started ringing, Xue Jiuyue suddenly thought: Liu Che was more accurate than the navigation system in familiar surroundings. So, he shouldn't have sprained his ankle in the hospital unless he was in an unfamiliar environment. The last time he'd been to an unfamiliar place was last night when he was watching a movie with her. Could it be that she fell asleep and Liu Che sprained his ankle? Then why did he seem normal when he was walking this morning?

No, that's not right. When I saw him leaving this morning, I did feel like something was a little off, his movements a little stiff. Was Liu Che forcing himself to hold it in?

After figuring it all out, Xue Jiuyue felt a mixture of self-blame and deep emotion. "Mending the fold after the sheep have been lost is the right thing to do"—though the idea was a good one, Xue Jiuyue's approach to caring for someone was quite amateurish. At the pharmacy, she bought nearly every medication she could think of, and not satisfied, she even bought a wheelchair before leaving.

"This, this..." Sitting in the wheelchair Xue Jiuyue bought, Liu Che was surprised, moved, and speechless when he learned that so many medicines had been purchased. He raised his eyebrows at first, then returned to a gentle smile, but his eyes and lips were still trembling slightly, but in the end he didn't say anything.

Xue Jiuyue was puzzled by his rich facial expressions. "What's wrong? Are you unhappy?"

"No, no, I'm just too moved." Liu Che hurriedly explained, "It's just, it's a waste of money. My foot will be healed in two days at most."

"Well, next time, bah bah..." Xue Jiuyue realized that she had said the wrong thing and hurried to make amends, "Bad things don't work, good things do..." This was the way her mother taught her to make amends every time she said something wrong when she was a child. Xue Jiuyue said it subconsciously in a panic.

The childish innocence immediately made them both laugh.

"It's better to be prepared. The moon waxes and wanes, and people are subject to misfortunes at any time. No matter what happens in the future, you have the medicine you bought, right?"

"No, I hope you will be safe and sound."

"Okay, okay. Even if everything is fine, you'll feel at ease, right? If you feel at ease, you'll walk steadily."

"Puff..." Xue Jiuyue laughed again, "You can even make this up. I didn't realize you were so good at sweet talk."

"I, I..." Liu Che was in a dilemma. It was not right to say anything, nor was it right to not say anything. His face turned red.

"Okay, I won't tease you anymore! I've never taken care of anyone before, so just make do with it..." Xue Jiuyue's voice gradually became lower, and her face became redder than Liu Che's with embarrassment.

"I'm very grateful and deeply touched!" Liu Che said, leaning back in his wheelchair. He then explained, "Look, it's more comfortable than my chair. And, I'm telling the truth. When I feel at ease, I walk more steadily. It's the butterfly effect."

"Butterfly effect?" Xue Jiuyue couldn't help but repeat it as she felt enlightened.

"Well, what's wrong?"

"Yeah, the butterfly effect. Why didn't I think of this before?"

The reply was completely off topic, and it was obvious that Xue Jiuyue's train of thought had already reached "a line of egrets flying into the blue sky".

Liu Che put on a gentle smile and waited quietly, without making any sound so as not to disturb Xue Jiuyue's thoughts.

After about a cup of tea, Xue Jiuyue came back from her own world and said excitedly: "I found the answer!"

"The answer? Could it be..." Liu Che also became excited.

"Sorry, that's not the answer!" Xue Jiuyue quickly said, understanding what Liu Che was concerned about and fearing he would be disappointed, "But I'm also very happy. I solved a problem that has puzzled me for a long time! Let me sort it out and see how to describe it to you."

"Well, no rush."

"Do you believe in fate? Oh, that's not right..." Xue Jiuyue hadn't figured it out yet, so she quickly changed her words, "Do you believe in predictions? No, do you think the future can be predicted?"

"Don't believe it completely."

"No, that's still not right. It didn't start from here. At first, I often had a feeling that I could predict the future. Many things happened within my expectations. Gradually, I found that I wasn't the only one who had this feeling. Many people had similar experiences or thoughts. I began to wonder if everyone could predict the future."

"Hmm, interesting."

"I once suspected it was a 'sixth sense'. But someone told me that the so-called 'sixth sense' is based on subtle details."

"Yeah, that makes sense."

"I agree, and that makes sense. Now I'm a little confused. Until one day, I saw the weather forecast. It suddenly occurred to me that any prediction about something that hasn't happened yet could be called a prediction! Later, I reorganized this idea, and I think predictions can be broken down into four types. The first is scientific prediction, which is based on objective laws and scientific methods. The second is empirical prediction, which is a probabilistic prediction based on past similar or similar situations. The third is sensory prediction, which is a hunch formed by the brain based on a comprehensive assessment of various acquired information. This acquired information includes information we're already aware of, information we've ignored but have already recorded, and the subconscious information you often tell me about. What we call a 'sixth sense' falls into this category. The fourth type is metaphysical prediction, which includes various forms of divination, as well as the legendary "spontaneous inspiration" and finger calculations. That's all I've summarized for now. It's just that sensory predictions and metaphysical predictions are often confused, and I'm still not quite sure how to distinguish them."

Liu Che followed Xue Jiuyue's line of thought and nodded in praise, "That's quite remarkable. It's indeed insightful."

"Don't flatter me blindly. I just came up with this when I was free at the cafe. I haven't looked up any related theories online, and I don't know if anyone else has the same or similar ideas. I don't think it's necessary. It's just for my own amusement."

“It’s good to be able to think for yourself without being influenced by other people’s ideas.”

"Xiao Ming, you're getting better and better at being a supporting role!" For a moment, Xue Jiuyue even "predicted" that Liu Che's words would be no less spitting than "spitting" if he let go of the conversation, but her attention was not on that at the moment. "When I think about this, it can be said that basically everyone can predict the future. We can even say that each of us takes actions in the present because of our predictions about the future. For example, when I walk, it is because before I act, I predict that I can move forward by taking a step, so I take a step. Originally, this mental game of mine was over, and I didn't think about it any further. But one time, I..."

Xue Jiuyue thought about the wording for a moment before continuing, "I dreamt of a sentence that I couldn't explain: 'If the future cannot be changed, then are my predictions useful? If the future can be changed, then are my predictions accurate?'"

“Why do we have to answer this question?”

"It's obvious that the predictions in this question refer only to what I call metaphysical predictions. If I can't answer this question, then my theory that everyone can predict the future doesn't stand up to practical scrutiny."

Liu Che didn't say anything this time, but just shook his head slightly. He probably hadn't caught up with the rhythm yet.

Xue Jiuyue felt a sense of accomplishment that even Liu Che was puzzled. She smiled and explained, "Everyone can predict the future. Actually, the key point is the metaphysical prediction part. If it is only the first three predictions, then they are well known and do not need my summary. So I must theoretically solve the problem that everyone can make metaphysical predictions. This requires practical testing. If everyone's predictions of the future are inaccurate, doesn't that mean they can't predict? The accuracy of predictions is related to that question. The future we encounter is different from the future we predicted. Is it because our predictions were inaccurate, or because the future has been changed?"

"I see!" Liu Che suddenly realized something and stood up excitedly. "So you were thinking of the butterfly effect! Because everyone can predict the future and make changes based on the results of their predictions, according to the superposition of the butterfly effect, the future we encounter will no longer be the same as the future we predicted."

"Bingo!" Liu Che hit the nail on the head, making Xue Jiuyue very happy. "Xiao Ming, you're really good at answering questions quickly! But you have to sit down first."

Liu Che only realized he'd been too absorbed in his thoughts after hearing this. He smiled and sat down quietly, further organizing his thoughts as he spoke. "If only one person, or a very small number of people, could predict the future, then we'd face the question of accuracy, and thus the paradox you dreamed of. Your proposal, that everyone can predict the future, perfectly solves this problem. Regardless of the facts, the logic is self-consistent."

"It's not just logically self-consistent. Truly everyone can predict it. For example, if a cup falls from the edge of a table, everyone watching can predict it will fall. The person closest to it, motivated by this prediction, reaches out to catch it. In this way, the future experienced by everyone else, except that person, will be different from the one they predicted, because the future has been changed."

Xue Jiuyue's explanation made sense, but Liu Che propped his head on the wheelchair armrest with his right hand, clearly lost in thought. After a few breaths of silence, Liu Che slowly asked a question, "What if no one caught the cup and it fell to the ground? Everyone's predictions would simply give two possible outcomes—either the cup would break or not break—but there's only one answer. How do you explain this?"

"Is the weather forecast 100% accurate?" Xue Jiuyue asked rhetorically before offering her own explanation. "Why are we so tolerant of scientific and empirical predictions, allowing for errors and accuracy, but have zero tolerance for metaphysical predictions? We must demand 100% accuracy."

"What you said really makes sense. There is indeed such a blind spot."

Although Liu Che also confirmed this statement, Xue Jiuyue did not stop there. She continued to delve into it, "Furthermore, even if we put aside the issue of accuracy and the fact that whether the cup breaks or not is actually a matter of empirical prediction, what you are actually asking is, if a prediction about something is about to happen and the person making it does nothing, in other words, reducing the butterfly effect to a negligible level, and it is still inaccurate, does that mean that not everyone can predict the future?"