RE:I hadn't realized just how far behind these kids were from the generation before them, but you're so right. The Marauders' Map would be something that very few of them could pull off, with the exception of Hermione.
Personally, I think that, if they hadn't found the Marauder's Map, Fred and George would have invented it. However, among Harry, Ron, & Hermoine there seems to be a lack of inventiveness inconsistent with the generation before them. Even the Half-Blood Prince was way ahead of them. Without his notes Harry couldn't have made it through class.
I have to admit that I didn't figure out the Half-Blood Prince's identity, as you apparently did. I was hung on Hermoine's guess that he was a woman, based on the handwriting, and the fact that the book was nearly fifty years old, which would put it near Voldemort's time, rather than Snape's. (Of Course we had already been told that Voldemort was not the Half-Blood Prince, so I knew it wasn't him). It did occur to me that the notes could have been written long after the books publication date, which it apparently was (Snape wore hand-me-downs, so it figures the books would be, too). I still have trouble believing that, after six years in his classes, none of them could recognize his handwriting. If I had had a male teacher that wrote with a feminine flourish, it would have been quite the joke in our school.
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