Im lost wat what does "how strange" means tell meh

I think he means that it was strange that he kissed Nakyum

it means like, how strange he’s feeling this way, or like- it’s hard to explain

He felt weirded out because for him it's strange that he was so worried and cared so much for nakyum (he thought he passed out again and got sick, but it turned out that nakyum's just sleeping)