Since this always comes up. It is not explained satisfactorily in the book why he can suddenly see them now, but couldn't at the end of the last book (or before that, as his mother died in front of him). From what I understand, however, it is not merely about having witnessed death, it is also about having processed that experience. To have understood it. I like this as an explanation.



I also notice that Hufflepuff's philosophy of teaching is the one that prevailed in Hogwarts as a whole. I like this sneaking in of the influence of Hufflepuff. It happened in the last book as well, with Cedric as the best of his year.