To be precise, my passion for reading started five years ago, thanks to a friend I met online.

He loves sci-fi, but since becoming myself a a fan of Star Wars myself was completely out of the question, I decided to give reading a try.

Flow. You could also write "But since me becoming a fan of Star Wars was completely out of the question,".

Again, I immediately ruled out sci-fi out and settled for novels.

Sometimes you can split a phrasal verb apart. Like "Please throw that can out." The phrasal verb here is "throw out" and it's still clear with "the can" in the middle that you're talking about throwing out the can. However, the way you wrote this, "ruled sci-fi out" doesn't immediately flow. I would suggest that you maintain the phrasal verb "ruled out" alone, and then put what is being ruled out (sci-fi) after.

My friend told me that among his favorites was Jim Harrison and Murakami, but since finding books of the former was impossible, I fetcheound one of Murakami’s books.

"Fetched" is very specific. It means to get something but for someone else, and something that's easy and a small task to do. You could fetch a pen for someone, if the pen is on a nearby desk and they're sitting down. You could fetch the mail, as it's a short walk to the mailbox. Unless you were walking over to a bookshelf to get the book in question, I don't think "fetch" is the best word here.

But I finished it though, and I ran to tell my friend my thoughts about his recommendation.

However, he only listened to me and didn’t say muchdidn’t say much and only listened.

Flow. This feels more natural.

Therefore, I just kept the habit to myself but without trying to impose any author or book.

I'm not sure I understand what you mean by impose.
Do you mean you didn't share your experiences reading with your friend? In that case, I would say "I just kept the habit to myself without trying to bring up any author or book."
Impose can really only be used in certain situations. You can "impose on" someone's kindness, as a very common phrase, meaning to take advantage of their kindness. Governments can impose fines, meaning to force fines on a populace. Generally speaking, "impose" is usually followed by "on".

Today, we remain friends, and are as different as we were five years ago.

However, thanks to him, I've discovered a bunch of Latin American authors I knew nothing about, even Chilean authors I hadn’t heard about before.

That’s how I’ve learned that even though two people can be complete opposites of each other, there are still some mysterious things that can hold a friendship together.

I just have no patience when it comes to helping someone to learn my language, and he is of no use in everanything related to helping me with my English.

It’d be nice to begin this story by saying that this is a habit that I discovered in my infancy, but that would be far from the truth.

Awesome sentence. "In my infancy" might be a bit too early in life. Infancy = the time of being an infant, although it can be used metaphorically, as I suspect you are doing here.

At that time we got along very well, but I always had the feeling that we had nothing in common, and since he had shared with me some of his hobbies, I tried some, just to see if we could find some common ground.

Pretty long sentence, but because the others around it are short, it works well!

Again, I immediately ruled sci-fi out and settled for novels.

Grammar is OK but I don't follow the logic. You went from sci fi movies -> nope -> sci fi books? -> nope -> novels? You made me think you were going to read sci-fi books with the previous sentence.

My friend told me that among his favorites was Jim Harrison and Murakami, but since finding books of the former was impossible, I fetched one of Murakami’s books.

Great sentence! And OMG Murakami is so good! I just finished Kafka by the Shore :).

TheI chosen one was “Norwegian Woods”.

"The chosen one" might be a sci-fi pun you're going for. However, since it is obvious that YOU are choosing, it doesn't make sense.

If this choice was due to some "fate" out of your control, maybe this would work.

I don’t remember the plot very well, but I do remember that I found it quite absurd, —almost for teens, —so it was difficult for me to relate to the characters.

Consider using an em-dash here "—". This might be a good tool for you to have to get around these long sentences with (essentially) parenthetical phrases scattered throughout.

https://www.thepunctuationguide.com/em-dash.html

on my mac it's option-shift-dash

However, he only listened to me and didn’'t say much and just listened.

Grammar is OK. A bit redundant. And, well, if he "only" listened then that implies he said nothing.

At that moment I realized that, contrary to what I had thought, reading wasn’t going to be the glue I was looking for to hold our friendship together.

You like phrases like this ("contrary to what I had thought"). I do believe it's an adjectival phrase as I said before. Be sure to punctuate them well :) .

Therefore, I just kept the habit to myself but without trying to impose any author or book.

You impose ON something. e.g. "He imposed his preference in books on me.". Alternatively, you can impose as a state of being, e.g. "I don't mean to impose, but can I ask a question?"

In this context I don't really know what you mean.

I would guess you mean you don't want to impose your tastes on your friend, but you use "but" here. So you'd have to use "and" because it doesn't contradict "I kept the habit to myself"

Every time my friend gives me a book suggestion I take it, and I admit that most of the time I like them.

I don't follow the story, didn't you say you can't connect over novels with him?

That’s how I’ve learned that even though two people can be complete opposites of each other, there are still some mysterious things that can hold a friendship together.

Unfortunately, we do have something in common and that is o: Our inability to help each other with our native languages.

Try out the colon here.

I just have no patience when it comes to helping someone to learn my language, and he is of no use in everything related to helping me with myteaching English.