[Book Review] Don't Be a Perfectionist—Be a Completionist!!

There are times in life when you come across a book that touches you deeply. Even setting aside the grand title of corporate executive, Accumulation and Expression by Shin Soo-jung is filled with sharp yet warm insights that could only have been written by someone who has struggled, stumbled, and learned in the field. As you read, you encounter passages that suddenly snap you to attention. They are usually highly realistic, hard-hitting pieces of advice such as, “Don’t trust your willpower; trust your money instead and sign up,” or “Work expands to fill the amount of time available for completing it.”

We always dream of stepping confidently into the world when we are perfectly prepared. But Shin Soo-jung firmly shakes her head. Instead of being a perfectionist, she says, become a “completionist.” Repeating small cycles of accumulation and expression, going out into the world and taking action first, and improving the quality as you go is far wiser. The experience of throwing yourself into a new opportunity instead of turning it down, even when it may be somewhat difficult; the flexibility to appear smart without being stubborn; and the strength to draw clear boundaries rather than accepting losses because of a gentle disposition—these are what genuine ability looks like. Especially now that artificial intelligence has arrived, we live in a world where anyone can easily produce results in 95% of areas. In the end, the decisive final 5% that creates the difference comes from these attitudes, refined by being challenged and tested in the field.

Another part of this book that strongly resonated with me was its discussion of organizational culture. Shin Soo-jung says that trust and good relationships within an organization are not merely moral declarations. They produce a powerful return on investment, like an “additional salary” placed on top of one’s actual salary.

Building on this healthy trust, she presents generosity as the ultimate attitude that leaders and experts should possess. Personally, the passage that resonated with me most in the entire book was the one saying that if you clutch your experience and knowledge tightly because you are reluctant to give them away, they will quickly become relics of the past.

If it is frustrating to see nonexperts confuse the public with insufficient information, experts should not merely stand back and criticize. They should write more, speak more, communicate more, and reach out to the public. Rather than waiting for someone to discover you, you should repeatedly place yourself in environments where you can be discovered—through lectures, articles, or social media. Mentors, too, naturally strengthen their own abilities in the process of answering their mentees’ questions. Even if it does not return as an immediate, visible reward, the process of organizing and explaining what you know and connecting it with the world ultimately helps you grow more than anything else. Knowledge that is held onto will decay and disappear, but the moment you let it flow into the world, it becomes your most powerful weapon.

Accumulation and Expression

Shin Soo-jung 2026 Woongjin Knowledge House

Instead of trying to change yourself, change your environment, change the people you meet, and above all, change the content you consume.

For an organization to do better, high performers must be enabled to exercise their abilities more fully. At the individual level as well, rather than trying to compensate for weaknesses, you should maximize the areas where you can make use of your strengths.

Repeat small cycles of accumulation and expression. Do not wait until you are perfect before stepping out; improve your level of completion as you go.

The essence of negotiation is not defeating the other party but achieving a win-win outcome in which both sides succeed. The first thing to do is understand the other party’s interests.

The true power of a crisis lies in making you think and act in ways completely different from how you did in the past.

Creativity and innovation emerge when an outsider enters a field and becomes a peripheral insider with an internal perspective. People who move across boundaries and make connections are more likely to create new forms of creativity and innovation.

When a new opportunity comes along, do not turn it down. Even if it requires some effort, creating something new can become another addition to your portfolio and an asset that opens the door to the next opportunity.

The decisive point is now the final 5%, because everyone can already produce the rest, thanks to AI.

Mentors also make their abilities more solid by teaching mentees and answering their questions.

Three ways to develop your abilities:

1. Share what you understand: Structure your thoughts in writing or visual form and share them on blogs, YouTube, social media, and other platforms.

2. Teach directly and answer questions.

3. Improve through feedback.

When recruiting new talent, you must take a clear-eyed look at whether that person’s abilities come from their individual competence or are more attributable to the colleagues and systems at their previous company.

Be careful about jumping to conclusions. The less capable a person is, the more likely they are to overestimate their level, while highly capable people tend to underestimate their own abilities (the Dunning–Kruger effect).

We are entering an era in which diligence, consistency, and quiet perseverance are once again becoming powerful. Even those who lack innate genius can overcome that limitation by applying AI to persistent effort.

Whatever you do, start lightly. Experiment on a small scale, repeat, and make gradual improvements. This is far better than being unable to start at all because of the pressure to prepare perfectly, or starting too heavily and becoming exhausted before stopping.

Do not avoid feedback. In the end, those who accept it, even when it is uncomfortable, go farther.

Instead of being a perfectionist, become a completionist. Do not worry about doing it perfectly; just do it.

Records create opportunities.

One thing people who continue to grow have in common is that they learn humbly and consistently. They keep learning until the day they die.

The more an educational program requires you to actively use your body and your thoughts, the more effective it is.

Even if your willpower is strong, it is a good idea to seek an expert at the beginning. Rather than doing nothing but worrying, it is better to spend money. If you calculate the time lost to worrying and the time wasted using the wrong approach, it is by no means expensive. It is actually cheap.

For ordinary people, do not trust your willpower; trust your money. If there is something you have been wanting to learn but have only kept in your mind, spend the money and sign up right now.

Work expands to fill the amount of time available for completing it (Parkinson’s law).

For your abilities to genuinely improve:

1. Set a higher goal and engage in deliberate practice, and

2. Question the methods you have been using.

An organization can grow sustainably and healthily only when it supports the growth of its members.

A leader is someone who enables the organization to grow even in their absence and leaves behind members who have grown through them.

As a company grows, you may actually become less busy. The smaller the company, the more important speed is.

As you move up in rank, the important things are:

1. Focus on essential goals and strategy.

2. Minimize impulsive instructions.

3. Spend time in the field and on creating value for customers.

Appear intelligent, but do not make enemies. Even when a decision differs from your opinion, follow it without complaint. State your views clearly, but do not be stubborn.

Pay close attention to legal and ethical issues and to loyalty.

People with gentle dispositions can make even simple tasks feel excessively burdensome. People who cannot be firm easily attract those who want to take advantage of them. That does not happen around people who draw clear boundaries. ... If a particular type of problem repeatedly comes only to you, you should take a moment to wonder whether something is wrong.

Use 80% of your energy to maximize your abilities and performance at work, 10% for long-term investments, and 10% to prepare for your future career.

When you achieve something, remember the people who worked with you. Make their contributions clearly known within the organization and share the results with them. Do not blame others even in difficult situations.

Leaving well is important. There is no reason to let resentment grow or leave one another feeling uncomfortable. ... The person in the stronger position should show a little more generosity and acknowledge the other person’s efforts over the time they worked together.

Empathy, sincerity, and small acts of consideration exchanged when people are in difficult circumstances create genuine trust.

Let what you give flow away like a river. But carve the kindness you receive into stone.

The highest achievers had a certain toughness within their kindness. ... When necessary, you must be able to refuse, draw firm boundaries, and maintain enough confidence to appear shameless at times. You must not give in to unreasonable demands, must respond immediately to gaslighting, and must be able to block unnecessary emotional drain yourself. Give first, but also know how to become cool-headed when necessary and respond firmly. Negotiation experiments also suggest that the strategy that produces the best outcome for both sides is “an eye for an eye, a tooth for a tooth.”

You should be grateful to the people who caused you frustration because they enabled you to rise again, break free, and live a changed life.

Trust, good relationships, and a good culture do not solve everything, but they create an effect like an “additional salary” placed on top of one’s actual salary. ... It is a strategic choice with a very high return on investment.

In most areas, you simply need to take action. ... Do not stop at learning something new; combine what you learn with your existing experience to make your own tools stronger.

Some degree of boldness is necessary early in your career. Excessive humility can cause you to miss opportunities. At first, you need to show your presence to attract attention, and opportunities arise once you have that attention. In your younger years, unfounded confidence and fearless challenges act as sources of energy. The key at this stage is confidence and execution.

The key in the middle of your career is to reach a state in which the organization does not explain who you are, but you yourself become the explanation—in other words, differentiation and personal branding.

The key in the later part of your career is the power to share based on your competence, as well as influence.

Even if you have ability, it is almost the same as not existing if no one discovers you. ... Change course in ways that allow people to discover you, and make your thoughts and knowledge public through lectures, presentations, reports, columns, social media, and other channels. ... It is far more realistic to place yourself in an environment where you can be discovered than to wait for someone to recognize you.

Show and present your achievements and value in various places. Meet people, try to expand onto a larger stage, and take action. Contact influential people who may recognize you first, and build weak ties. ... Make active use of tools such as social media and blogs. You should intentionally increase the probability that someone will discover you.

Expertise does not automatically lead to influence with the general public. ... If it is frustrating to see nonexperts confuse the public with insufficient information, do not criticize from the sidelines—participate. ... An expert is not someone who stands back and comments; an expert writes more, speaks more, communicates more, and reaches out to the public.

Experts, make time and find the courage. Whether you write a book, create YouTube content, give lectures, publish more articles, or write a blog, share more of your expertise. Ability is not completed simply by accumulating it. It only becomes powerful when connected with the world.

Sincerity and consistency are necessary. People think about how helpful someone is to them. They are not particularly interested in how impressive you are.

You should not post random things on Instagram. The key is to provide immediate value. Clearly choose one topic and consistently provide value through it. Content focused mainly on yourself, or posts covering random subjects without a clear concept, receives almost no response. However, people are curious about what kind of daily life that person leads. That is not formal content; post it occasionally and temporarily in your Stories.

Important opportunities and insights are more often gained through weak ties—acquaintances you meet occasionally or loose relationships—than through strong ties such as your closest friends or family. ... Weak ties connect you with worlds belonging to entirely different organizations, industries, and perspectives.

No matter how tightly you hold on to your experience and knowledge, they become outdated knowledge after a little time. Whether through lectures, papers, articles, writing, open-source communities, or social media, it is better to share actively within what is permitted. There is also a high chance that it will return as an opportunity in some form someday. Even if it does not come back as a visible reward, the process of organizing, explaining, and sharing itself helps you grow.

Who tutors high school students? Professors do not, after all. It is college students who are only one or two years ahead of them. Even if you are only half a step ahead of someone else, you have enough to share.

Do not cling to what you cannot do; focus on what you can do. ... How well you perform when you are on the playing field matters, but so does your attitude and what you do when you are on the bench.