Why were they not ashamed by their nakedness (Gen 2:25)?

Their lack of shame at their nakedness shows how like children Adam and Eve were. The suggestion is that “knowledge of good and evil”—whatever this is, precisely (see below)—also brings a sense of shame at nakedness. Presumably, though in some sense perhaps it is no shame for the innocent, it becomes shameful for the sinful. Again, precisely what difference is discovered is not (as far as I can tell) actually explained in the text; the reader is left to fall back on his own adult sense of shame.