There’s an interesting essay on the reading order of the Chronicles of Narnia here. I read The Lion, the Witch, and the Wardobe first when I was eight or nine, then I realised there was a whole series so I went back and read them all in chronological order (because, like Mousme, I am mildly OCD about that sort of thing although I am slightly better now that I am a few decades older). But the points the essay makes about the reading experience if the books are read in publication order are interesting. After the first couple of times I read them singly and out of order according to my whim of the moment, although two summers ago I did read the entire series chronologically again. Both experiences are valid, simply different, as the author points out.