I read all off the Narnia books as a child and loved them (I started with A Horse and His Boy, of course). Having been raised as an atheist Jew, I was blissfully unaware of the religious subtext (friends raised otherwise don't believe me, but it honestly never crossed my young mind that Aslan could be anything other than a lion).

As a teenager, I learned that the Narnia series is in fact jam-packed with religious propaganda, and I felt as if I'd been sucker-punched or had nasty medicine mixed in with my dessert. I still like the books as literature (I think that Lewis is a much better writer than his pal Tolkien), but I detest Lewis' smug evangelism.

Greg, OTOH, had the books openly taught to him as religious allegory in Catholic high school and for that reason can't enjoy them at all to this day.