Many people only realize after turning thirty that the gap is often laid early on.

What's the use of studying mathematics?
A few days ago, I was chatting with a junior who works in quantitative trading. He now does high-frequency trading and risk modeling on Wall Street, and quite a few people in his team are from top American universities, Ivy League undergraduates, and graduate students in statistics or applied mathematics.
He said studying mathematics is very painful. When we talked about calculus, determinants, Taylor series, he immediately couldn’t smile. At that time, this kid also doubted what these things could actually do, and that was also the focus of our debate. I told him, you deserve to still be working a job now because you learned math but don’t know how to apply it practically.
The reason Mount Tai remains unmoved in front of you is because your mind has a framework. Life may deceive you, but mathematics won’t, because if you don’t understand it, you simply don’t understand it. Mathematical thinking has many uses in life, such as:
Breaking big problems into variables
For example, yesterday I was very anxious, but I didn’t know why. I broke down the problem of anxiety into possible causes: lack of sleep, work pressure, or relationship tension. Then I found out it was because a certain collaboration team was anxious, so I immediately called them and gave them a piece of my mind. Breaking a vague feeling into observable factors will significantly increase your sense of control.
Define the problem first, then express your emotions
When facing a problem, don’t panic. First ask yourself, what is the essence of this problem?
Is it a lack of time, or poor prioritization?
Is it not earning enough, or are there issues with cost control?
Then take out a pen and write down the problem clearly; half the solution is already there.
Replace fantasies with probabilistic thinking
Many rookie-style anxieties are essentially treating small probabilities as certainties.
For example, seeing a certain coin rise 30% in one day, and then fantasizing that if you had held a large position, you would have doubled your money.
Seeing someone post their gains in a group, and assuming others make money every day.
Losing once makes you think the market is targeting you specifically.
These are all typical probability illusions.
List conditions when making decisions
Any choice can be broken down into three questions: what are the costs, what are the benefits, and what is the worst-case scenario? When the worst case is within your acceptable range, your decision will be more decisive.
Treat ability with compound thinking
Losing 0.1% of weight every day may seem small, but after a year, you’ll find it impossible to stick with. Reading, exercising, learning—all are suitable for viewing through the lens of compound growth.
Over time, you’ll find that learning math automatically starts your brain modeling when you encounter problems. So if a child asks what’s the use of studying math, honestly, many formulas won’t directly appear in life in the future. But the focus developed during derivation, the habit of breaking down problems, will accompany them for many years.
Why am I relearning math now?
One morning, I wake up and find that the world’s advanced mathematics level has regressed by hundreds of years. I lazily sit in a calculus class, using L’Hôpital’s rule to solve a limit problem. Suddenly, a gasp spreads around me, “What? He actually solved a problem that has remained unsolved for decades! Could he be… a figure in the history of mathematics?”
Suddenly, a foul smell fills the classroom. I search every corner but find no cause. Until I lift the pillow and open the envelope, and see the moldy dreams in the corner and my decayed ideals.
I fold the letter I wrote in my youth, place it under the wobbling table leg—perfectly fitting, just right.