The reason I finally realized at 22 that I should read books while I can

"You should read a lot of books while you can."
I never understood the reason for that for a long time. That's why I barely read any books until I was about 20.

At 22, I was finally able to explain it in my own words.

"You should read books. Because books are the ultimate means of 'exploration'."

The AI that has been a hot topic recently learns using two processes: 'deepening' and 'exploration' (machine learning). Deepening means improving little by little. Exploration means trying methods that are completely different from what you have done before.
For example, going to a classroom to practice calligraphy to improve is deepening, while going to a modern art museum to experience completely different art is exploration. Of course, as a result of exploration, there is a possibility that you might receive strange inspiration and take a step back for a moment, but if you only do deepening, you probably won't reach the level of someone like Soun Takeda.

Books give you the chance to explore.

In high school, I only focused on deepening my knowledge of mathematics for entrance exams, but just before I turned 20, I encountered a book called "FACTFULNESS." It is a global bestseller about how the world is not as bad as you think when you look at it through numbers. Knowing that math was being used in such an interesting way was my first exploration through a book.
Since then, books have helped me explore many things. I learned about the fun of team sports strategy from "Haikyu!!", was taught the thrilling sensation of art and mystery from "Canvas of Paradise," and had my way of working fundamentally changed by "Essentialism" (Issue Kara Hajimeyo).

Books are the best means of exploration.

There are many ways to explore other than books. Or rather, almost anything you 'don't usually do' can be called exploration. For me, going to an art museum, doing calligraphy, or traveling abroad are all generally forms of exploration.
However, I think what sets books apart from other forms of exploration is their ease. The exploration you get from spending 3 hours reading 200 pages of a 1,000-yen book might have a volume comparable to standing under a waterfall. To put it crudely, the cost-performance is overwhelmingly good.

The chance for exploration is not given to everyone

I often hear people say, "The Akutagawa Prize-winning work wasn't interesting at all," and I think I often feel the same way. (Since I've only been reading for two years, I've hardly read any Akutagawa Prize works...) On the other hand, it is also a fact that there are judges who highly evaluated those works. This difference is probably due to the amount of reading done so far and the experience of challenging difficult books.
To get the chance for exploration from books, you have to read them. I think you need to challenge yourself with new genres and difficulty levels to polish yourself, because just reading the same kind of books is closer to deepening.

That is why you should read books

I think it's fine if it's manga, novels, study-related books, or maybe even poems. Of course, books have other interesting aspects besides exploration...
However, I found 'exploration' through books to be very interesting, and I think it's better to do a lot of exploration while you're young. That's why I think I'll eventually become an old man who keeps telling people, 'You should read a lot of books while you can.'