[Donghua] Klein’s behaviour in tarot gatherings

So I got a question that’s been scratching my mind and seems like donghua just skips some source material content. In tarot meetings (esp. first one) Klein somewhat doesn’t know anything about the world he is in yet he talks and acts like he’s been there forever. The tappings on the table, acting like he is above the tarot members and stuff. I mean don’t get me wrong he seems he is above them but he shouldn’t have any clue about that stuff but he acts boldly. In the novel, is there any explanation whatsoever to this? how come is he a know-it-all or he makes something up but turns out to be true.