I am again re-reading Harry Potter and the Deathly Hallows - and as I began to break down in tears in a cafe (halfway through 'The Missing Mirror' chapter), and was forced to lay the book aside and stop reading or risk dissolving into a blubbering mass; I realized for the nth time that many adults are missing reading this wonderful book for the simple reason that they are either unable or unwilling to read children's books.
The problem is that, according to conventional wisdom, the Deathly Hallows can only be approached via the preceding six Harry Potter stories; two of which are designed for intelligent (approx) eight year olds, the next for ten year olds, two more for 12-14 year olds, and only the last two volumes of being fully adult novels.
But, despite that I enjoy reading 'children's literature' - this was in fact not how I personally approached the Harry Potter series.
I had seen all the early movies (which I found entertaining but not deep - because the deep stuff has been censored or edited-out); but after abortive attempts to tackle the early HP volumes, I finally read some chunks of the Half Blood Prince, due to my inability to understand the movie (becuase it incompetently missed-out key facts).
Then, my daughter got very keen on HP and began reading through the series - and in order to be able to discuss it with her, as she progressed through each volume, I read the corresponding plot summaries on Wikipedia/ Harry Potter Wiki - then I eventually read the whole of Deathly Hallows and was amazed, astonished, delighted - and extremely moved by it.
So I went back and read all the earlier stories, but not in chronological order (I have read the whole series, aloud, in chronological order since then).
Anyway, my point is that, so long as it is regarded as essential for adults to read through the Harry Potter stories from the Philosopher's Stone onwards before tackling the last books, for so long will many adults be prevented from appreciating the wonderful last book.
In fact, in terms of both structure and style, the Half Blood Prince and Deathly Hallows make up a unit: therefore, the solution is that they should be published together in a single mega-volume marketed to adults - and with all the necessary back story provided in the form or a Foreword or Preface, plus a few explanatory notes (probably as footnotes).
This would be ideal: but in the meantime I invite adults to plunge straight into the Half Blood Prince followed by Deathly Hallows, having read the back story on Wikipedia, the Harry Potter Wiki or somewhere similar; and looking-up any puzzling references as you go.
Because, you really don't want to miss these books - especially if you are a Christian.