She "WAS" an adult but she has regressed back to being a child so she naturally acts like one and she isn't simping for child cause she is a child an x spoiler they both have memories as their older selves but they aren't their older selves the only thing thing they've gained is a more developed thought process than the average child in my opinion
Logically, if the body shrink to that age, then the brain should have been shrink into the same state. Even if she was an adult before, due to her being in a child body, even her brain and her cognitive processed like a child. This is the most logical things that should have been done in all manhwa about time regression.
Everything has reversed back tho, therefore just like her body has regressed in time, so has her frontal lobe. Just because she’s got memories of the past doesn’t mean her brain is fully developed to access all that memory. Plus she was very spoiled as an adult, and you can clearly see she’s remembering scenes from the past. Therefore she most likely doesn’t have her full memories back. The frontal lobe of a child vs that of an adult is very different, even that of a teenager assuming it wasn’t fully developed by the time she died. Just like how she easily cries over the slightest thing or how she’s admitted to getting tired faster than before, the mind her body possesses at that time has its disadvantages.
Bit of a stretch to assume that the author went about it with biologyneuroscience, and not just vibes. She has knowledge from two past lives, the one on Earth and the previous one in that world, so definitly not only that of a teenager. And we've already seen that she's able to access all the memories that suit her. Nevertheless, she very much is able to think way more advanced than a child, e.g. chapter 17/18 where she thinks about cultivating the herbs and ways to do so, but then she goes back to thinking like a child. I'm not saying her body hasn't regressed, so her emotions and her tiredness are very much expected, but she does not think like a person that has memories from past lives.
I think that she does think like a person who has regressed to an extent bc she was able to make a plan about how she wants to change. However because of the maltreatment at the temple both her growth and her personality/maturity seemed to hve been stunted. She even acknowledged this when she admitted to acting out even more than usual in her first life because she felt like everyone was comparing her to Diana. At one point she even says that she wants to b better than that in this life, but that’s an active goal and is probably just foreshadowing her character growth. If she had gone back in time and just fully changed her personality without gut any trials I think it’d probably b harder to have her relate to characters like Joshua, who dont remember the past, plus on a personal level I feel like it wouldn’t b as satisfying to read.
Isn't she supposed to be an adult that regressed into a child's body, and not an actual child?? Why is she constantly thinking and behaving like a child? I get that she has to "act like one, but come on. Also why is she simping for a literal child?