Although the unprecedented "Pottermania" that gripped the Western world until approximately a decade ago has now receded; the opinion I formed of the Harry Potter series some 15 years ago as being a work of genius has by now survived multiple (six?) complete re-readings - plus further dippings-in.
I find my appetite for the Harry Potter books undiminished, and get more from every time I encounter them.
I was late to the series, having sampled and discarded a few of the "Philosopher''s Stone" and a couple of earlier books.
I kept falling at the fence of The Dursleys - especially in the first book, where this part of the plot takes up many slow and tedious chapters before Harry eventually enters the Wizarding World.
It therefore does not surprise me that this book was rejected so often before finding a publisher - if the editors were anything like me, they will not have got through the early section to reach the good stuff later.
Those parts of the books featuring the Dursley family continue to strike me as mostly unsuccessful, and written at a much lower level than the rest.
The Dursley characters are cartoonishly unbelievable, when they are not figures of oppressively heavy-handed juvenile satire.
Furthermore, the way that Harry (who is believable, and with whom we empathize) is physically and psychologically tormented by the Dursleys in the first and other early books; is so appalling that it is either viscerally horrific and overwhelms the other elements of the story, or else we are compelled to adopt a superficial and appropriately cartoonish level of engagement in our reading (which is what most people seem to be doing).
Thus it was not until 2009 that I actually read the Potter books; although I had watched the movies as they came out, with no great depth of appreciation - except for "The Prisoner of Askeban"; which is (in retrospect) unsurprising, since the movies had been almost completely filleted of profundity.
Then in 2009 I read the second-to-last book "The Half-Blood Prince" before launching into the crowning glory and triumphant vindication that is "Deathly Hallows".
After which I went back and read all the earlier five books, albeit probably not in order of publication.
And "I was hooked".
Harry Potter has since, over a span of fifteen years proved to be robustly enjoyable across a wide range; from its large cast of memorable (indeed archetypal) characterizations; its abundant and delightful humour (surely this is an under-rated facet - these books are very funny in parts); the richness of invention, excitement, and adventure; the very impressive plotting (mastery of the full range of techniques of an expert murder mystery writer was evident); and most importantly these books spiritual depth and edification across the series.
The accomplishment of such a long coming-of-age time-frame, for several major child characters as well as Harry, makes these books unique in my experience.
While I have no idea how the Harry Potter book-series will fare in future; in terms of mass marketing and cultural significance; for me they have easily passed the test of repaying repeated engagements over a long time span.