no, it's not. what's more logical is that he should have already had the wariness level 100 considering he suffered verbal abused and bullying from everyone including strangers way back in chapter 1. it's not about him having a prep time but him not having the "stranger danger" mindset. he's literally aware that he's weak as he said in chapter 1 so that's why he tried everything from learning martial arts to learning magic. so being weak, he should've had the self-preservation of a cockroach but not this fucking moron.
my problem with him is that he fucking rushed to the guy despite knowing it being a dangerous labyrinth but he's like, oh look it has a silhouette of a kid, i better run towards this shitling with no thoughts whatsoever even though in every corner there is a dangerous trap or an ambush waiting for us just previously