Because you mention reading "the first book": There's actually a spirited debate about what the proper order is, and my companion article on it just got published (https://medium.com/books-are-our-superpower/have-we-been-reading-the-narnia-series-out-of-order-all-this-time-2633cdd24e07). I'll probably get called a fascist in the comments over there, as well, but this time for something other than my opinion that discrimination is bad