42 Seoul selects students for its main program through a test called La Piscine.
In Korea, there are probably lots of people preparing in advance through different routes, like La Piscine prep academies, people retrying after failing once, or friends of current main-program students. We can only guess who these people are, but I imagine that makes it hard to go through La Piscine with a completely relaxed mind.

If you do not know anything about 42 Seoul through people around you, it can feel overwhelming to prepare. Those people usually search a lot of blog posts to gather information. Since many cohorts have already been selected, if you collect enough scattered information, you can figure out how to prepare and what you will do once you get there. Still, I think there is also some fun in going in without knowing all of that and learning it along the way.
Some people might think, "Getting selected is what matters, so who cares about fun?" But looking back, the experience of La Piscine was the most fun part of life at 42 Seoul. Many main-program students say they regret not spending even more time on peer learning during La Piscine. The main program is also fun because you get to push through the common core, but once you become a main-program student, there is a surprisingly high chance that you will not be in the same place with people working on similar assignments the way you were during La Piscine. That is why meeting as many people as possible during La Piscine helps later too. When you enter the main program, it can keep you from staying away or feeling lonely because you do not know anyone.
Even if you have lived in Korea's endless competition since childhood, when there is something you do not know during La Piscine, try figuring out why you do not understand it, asking others and learning from them, and teaching what you know in return. Nobody knows everything, so try sharing information you can exchange with each other and learning from one another's methods.
My own strategy for passing La Piscine was to be kind to as many people as possible, stay on good terms with them, be someone helpful, arrive early, and leave late. I do not know whether that really worked, but I also got into the main program even with a not-so-high level.

Still, the reason I am writing this is because I hope nobody comes to La Piscine completely unprepared, decides it does not suit them, and gives up a hard-earned opportunity halfway through. Even when I joined La Piscine, it was painful to watch good people I hoped would make it with me get scared or overwhelmed, or show up only for the stipend, or try to solve everything alone without cooperating.
I cannot go into every detail, but I listed some books below that can help with La Piscine.
Even if you are not applying to La Piscine, I still recommend reading them at least once because they can help your developer career.
I truly hope good people come as students!
- 맥 쓰는 사람들의 macOS 모하비 - It is fine to learn this from YouTube instead of a book.
- 모두를 위한 리눅스 프로그래밍
- 리눅스 입문자를 위한 명령어 사전
- 윤성우의 열혈 C 프로그래밍
- 깐깐하게 배우는 C
You do not have to learn only from books. Videos and online documents are also great.
One who is too insistent on his own views, finds few to agree with him.
— Laozi