There are times when you suddenly have a thought like this one day.

“Where am I right now?”

Some people compare life to a marathon, and others to mountain climbing, but the period between ages 35 and 45 is a little different.

This stage is neither the section right before reaching the summit, nor is it the starting line.

It is exactly the waist of the mountain—the longest, the most tedious, and therefore the section where the most people give up.

It is an ambiguous point where looking up shows you still have a long way to go, looking down suggests you have climbed quite a distance, yet you cannot turn back down.

It is a time when you are out of breath, your legs feel heavy, and yet you do not know why your backpack feels so heavy. Inside that backpack are your parents' medical bills, your child's tuition, and loans you haven't fully paid off yet. That is why people's shoulders are always tilted slightly forward during this period. It is to bear the weight. The way to get through this time is surprisingly simple. You cannot throw away the backpack, but you can choose what to put inside it. Many people put stones in it. The car others like, the house others live in, the bag others carry. They put them in without knowing if they are stones or gems. However, as you climb the mountain, you realize at some point that not everything that sparkles is a gem. That some things are merely heavy shards of glass. The real gems are something else entirely. Numbers quietly accumulating in your bank account, emergency funds saved up unbeknownst to anyone, and the option to say, "You're the one who needs it," no matter what happens at work.

They go unnoticed when you carry them around, but on the mountain called life, they become a safety net more reliable than a rope.

People often look for style on the outside, but true style actually comes from within.

An expression not chased by credit card bills, a mind not waiting only for payday, and a situation where you don't have to force a smile in front of people you don't want to. That is truly the most expensive luxury item a middle-aged person can possess.

The next most important thing is your mind.

People say that the mind hardens as you get older, but to be precise, it is closer to stopping updating rather than hardening.

Just as apps on a smartphone stop running one by one if you don't update them, people also start to become incompatible with the world if they don't update the operating system inside their heads.

You may think you are still fine, but in the eyes of the world, you become an outdated model.

That is why curiosity is more important than pride during this period.

“Why should I learn that?”

If you start saying this, your pace has already slowed down.

Learning a new skill is creating one more way to make money, and learning new ideas is creating one more way to endure life.

Those with only one way to make money feel anxious, those with two feel stable, and those with three feel at ease. Ultimately, studying is not for the sake of exams, but to expand the options in your life.

And finally, perhaps the most important thing is your mindset.

When you reach this age, strangely enough, you hear a lot of news from those around you.

I heard someone bought a building, someone made hundreds of millions of won in stocks, someone started a company. At times like that, your mind feels quite strange.

On the way back after congratulating them, you find yourself stopping by a convenience store for no reason to buy a can of beer.

The journey home feels longer than usual, and you might let out a sigh for no reason in the car.

There is something you must remember at times like that.

Life is not the same test paper.

Some people are solving math problems, some are solving English problems, some have already finished their exams, and some have just started theirs.

Yet, we keep looking at the speed at which the person next to us is solving problems and think that our own exam is ruined. The problem itself is different to begin with. That is why ‘task separation’ is necessary. That person’s success is their task, and my life is my task. The moment you start spending energy envying others’ lives, the time to solve your own life’s problems disappears. Comparison is not a compass that shows you the direction, but rather akin to sandpaper that gnaws away at your mind. If you keep rubbing it, your self-esteem will eventually wear away completely. Instead, I hope you try thinking this: “I solved my problem again today.” This phrase is more helpful for enduring than you might think. Getting through the day might seem like nothing special, but it is actually a remarkable feat.

Feeding your family, holding out at work, maintaining relationships, and finishing the day without collapsing means you have survived another invisible war.

So, when you come home at night and no one is around, or before turning off the engine in your car, just say it very quietly once.

“You worked hard today.”

The ages of 35 to 45 are not a time for preparation; it is a time when you are already playing in a game that has begun.

It is akin to the first half ending and the time to catch your breath and take a sip of water before entering the second half.

The strategy needed at this time is simple: carry material things a little lighter, fill your mind a little heavier, and make your heart strong so it does not break easily.

Then, surprisingly, when you reach your 50s, the landscape of life begins to look a little different.

The road that used to look like an all-uphill climb—when you look back then, you will see that you have come quite a long way.

And at that moment, you will have a thought like this:

“Ah, I’m glad I didn’t give up back then.”