Responses
Pretty sure the military was her escapism in her first life. It is rules and order and gave her structure and something to focus on other than her pain. The same thing is happening now like you said, she’s defaulting to what she knows.
People need to chill and just enjoy the story. It has loopholes sure but it's fine enough for me since the plot is gearing towards fantasy rather than serious. If the author wants to really stretch the boundaries of fiction so be it. Let's give it a chance. I'd like to think she's really acting like that because of PTSD and loneliness. Scratch the part she was an adult before but think of it that she's adapting while grieving, twice at that. To cope with the absurdity of it all, she defaults to what she knows, to what she's accustomed to, in order to be rational. I've read a different manhwa that although she was an adult inside, she couldn't help acting like a child because of the body she's in. Like her intelligence couldn't manifest properly becauss her mental faculties hadn't developed properly. It could be the case here with the author's character settings.