This has been on my mind for a while. In Lucky Star Episode 18, Tsukasa Hiiragi lightly expressed her desire for having a pet dog. But she quickly got her dream crushed by her sister Kagami, who warned her about all kinds of problems that would be faced by a dog owner. At that point, Tsukasa had to agree with Kagami, and said something along the lines of "you really know much about this, sister." On hearing that, Kagami suddenly became bashful, turned her head away and said: "In the end I am also a simple-minded person, that's why I looked those things up".
It is this reaction of Kagami that does not make sense to me. Of course, I know that Kagami is a Tsundere kind of person, but I still see no reason to feel ashamed, or to emphasize your simple-mindedness here. After all, the difficulties of dog-raising that Kagami mentioned (walking, feeding, difference between a puppy and a grown-up dog etc.) do not seem like something that a high school student should look up to know, and no one would say that knowing these things stop you from being simple-minded.
Am I missing something deep here, or is it just Kagami designed to be over-reacting?