
how does he remember almost every item, monster and their weakness did he memorize the whole book or what?? IT WAS A SUPER LONG BOOK TOO OMGJ

Pretty much? I mean, YJH died and regressed over and over and over again.
It’s like game over and you can’t load your save file, so you must start over from new game. You cannot use auto play or skip dialogue, so you have to watch those lengthy conversation and movie and whatsit until you reach the part where you died previously and finally you can continue to the unknown territory. If you died, repeat from new game. Now imagine Dokja repeat this more than 1800 times.
So yeah he’ll know by heart, the prologue, the beginning scenarios, what items he should hoard, where can he get it, which monster to hunt, where’s the best place for grinding, etc.

YJH regressed multiple times is already mentioned in manhwa, no?
The game metaphor is my own interpretation after reading the novel though. I used this metaphor when my sis asked the same question and it’s easier for her to understand because she’s a gamer. Kinda.
My bad if it’s make it more confusing?

it isn't revealed in the beginning that he had it it was something he remembered later on when he was having trouble remembering something and decided to reopen the email from the author (that was when he discovered he had the only text version in the world) I don't remember exactly when he remembered it but thats how it happened in the novel
i'm glad isaac is a part of the adventure (●'◡'●)ノ he's a great character. i miss rena tho, where's my babygirl