My Fundamental Way of Understanding Reality

We Actually Live in a Four Dimensional Space

Today I want to share with you a fundamental way of understanding the world: seeing time as the 4th dimension of our reality. When you read today's title, “We actually live in a four dimensional space,” you might think I'm just trying to grab attention. After all, we clearly live in a three-dimensional world. Some sci-fi fans might imagine that there's an unseen dimension allowing aliens to appear instantly in our world from the 4th dimension, but that's just baseless speculation. However, if we change our perspective and consider time as a dimensional space, then our world is actually four dimensional, also known as space-time. This is a scientific concept first proposed by Albert Einstein in physics. Space-time has an entire theoretical framework, including how to calculate distances while factoring in time. But that's not my main focus today; what I really want to talk about is the impact of time.

My inspiration comes from a message left by a reader named Lemon. She wrote six years ago: "A longtime friend of mine asked to borrow money. She said she really needed it and, since we had a great relationship, I didn't think twice. I sent her the money without even asking for an IOU. But later, her husband came to me and asked, 'How much money did you borrow from us?' I was completely stunned—his wife was the one who borrowed money from me. It turned out she had been investing in stocks with millions involved, and I couldn't understand why she would do something like that. Was this really the same friend I had known for years? Two years ago, she paid me back completely, even though I never asked for it, showing that she still valued our friendship. But in the end, I lost a good friend. I wanted to reconnect with her, but she always seemed distant, which in a way was good for me. There was an irreversible crack in our relationship, something that could never be undone, and I had no choice but to move on. So, should we avoid lending money to close friends to prevent losing them? What do you think, Mr. Wu?"

How time transforms space

Before answering her question, let me share two stories about my friends.

First story: Chasing a dream from the past.

My friend Xiao Mei wasn't a top student in high school and didn't get into a prestigious university; however, she worked hard and eventually became successful in her career. Yet she always had a deep admiration for elite schools. Some prestigious universities, particularly those that are business minded, take advantage of people like her—Stanford University being one of them. Stanford offers two programs tailored for this kind of audience: one is a special short term MBA program lasting only two months but costing as much as a full year MBA program; the other is the visiting scholar program. While most visiting scholars at Stanford are there for academic research, a small number gain entry by making significant financial donations. A university official once told me about this, explaining that donating the equivalent of free postdoctoral research grants could secure someone a visiting scholar position complete with an office desk and an official ID. My friend was eager to attend Stanford's Business School or become a visiting scholar. I asked her, "At this stage in your life, with your career already established, why chase this status?" She insisted that it wasn't just about prestige; it was about fulfilling a long lost dream. In the end, she chose to be a visiting scholar. At first, she proudly posted photos of her ID and office on social media, but over time even she began to resent this behavior. While she continued to tell people she had been a visiting scholar at Stanford, privately she admitted that the experience didn't match the intellectual romance she had envisioned. She couldn't quite explain why. I told her, "The 40-year-old you and the 20-year-old you are two completely different people. The same campus experienced 20 years apart is an entirely different place. What you didn't get at 20 won't feel the same at 40, even if you were treated as a 20-year-old again."

Second story: A relationship that couldn't be recreated.

My friend Xiao Chang had a college girlfriend who was considered the campus beauty. They had a good relationship, but she was the dominant one in the dynamic. After graduation, as they started working, they spent less time together; with many suitors at her workplace, their relationship naturally faded. Xiao Chang, understanding the situation, let go without drama and focused on his career. He later went abroad for his PhD. Ten years later, after earning his doctorate, Xiao Chang landed a job at a multinational company and was sent back to China to expand their business; he became the second highest executive in the country. Meanwhile, his ex-girlfriend had married and divorced, ending up single again. When she heard about Xiao Chang's success, she reached out to see if he could help her find a job. Xiao Chang happily agreed—not just out of kindness, but because he still had feelings for her. To avoid workplace conflicts, he helped her secure a job at another company. They got back together, and everything seemed perfect at first, but within a year they broke up. Friends speculated that now being wealthy and powerful, Xiao Chang must have abandoned her for someone else. At first he tried to explain, but eventually he stopped bothering. In private, however, he confided in me, "She's not the same person I once knew." I told him, "That's true, but you're not the same person either. At 20 you loved the 20-year-old version of her, but if today were your first time meeting her at 30, you probably wouldn't fall for her. You're clinging to a past that no longer exists."

The power of time

Over a century ago, Einstein pondered a philosophical question: What are the fundamental conditions for existence? His conclusion was space and time. If either ceases to exist, the world itself would lose meaning—essentially, it would not exist. Since space and time are inseparable, changes in time naturally alter space. Imagine a ruler fixed at one end while the other end rotates; even though its length remains unchanged, its position shifts over time. Human relationships work the same way. Some things once missed can never be recovered. If you were once a struggling student with barely enough money for tuition and a thief stole your last bit of cash, preventing you from completing your studies, no amount of money later in life could fix that. In the first story, my friend missed the experience of studying alongside talented young peers at ages 18 to 22; no degree could ever bring back that youthful camaraderie. When the time for something has passed, it's best to let go. In the second story, people change. Two friends drift apart and stop communicating for a long time; even if they reconnect, they may find themselves strangers, as time has transformed them. Einstein's space-time equation shows that time influences space more than space influences time. If we apply this to society, we see that in a rapidly changing world, time's effects are even stronger, and we live in an era of rapid change.

Seizing the present to avoid regret

Understanding this reality means keeping three things in mind.

First, do things at the right time: study when you're in school, love when it's time to love, and settle down when the time is right. Delaying these milestones can make them feel unnatural later.

Second, let go of nostalgic memories: if past experiences conflict with your present, prioritize the present—you are no longer who you used to be.

Third, don't overthink the future; the future rarely turns out exactly as imagined as long as you avoid making decisions that will harm your future. Don't stress over uncertainties, and most importantly, never forget that time is the 4th dimension of our world.

That is my fundamental way of understanding reality.