I always think it's a bit funny how everyone has books that were absolutely crucial parts of their childhoods, and they are always completely horrified when they realize that other people never read them at all. I feel this way about all the Little House on the Prairie books most of all, because those were an absolutely enormous part of my childhood, and I would feel this way about Swallows and Amazons had I not always been aware that very few people I knew read them. I've recently acquired a friend who did read them (and even got to learn to sail, too, which I'm vastly envious of), and I was completely gleeful when I happened to make a reference to them (to Swallowdale in particular) and he happened to be around to get the reference.
Hand in hand with this, there are various children's books that I never read as a child, that even I am somewhat shocked I never read. I was, for example, rather surprised to realize that I had never read Winnie-the-Pooh. Whenever I go through those list of 100 best books, or books to read before you die, or whatever, I always hesitate over marking Winnie-the-Pooh, because I'm sure I must have read it, hasn't everyone?, but I don't actually remember reading it. I even own the book. But I was ferreting for something to read the other day, and I pulled out Winnie-the-Pooh and realized, no, actually, I haven't read this.
I read one of A.A. Milne's plays a while ago, Mr. Pim Passes By, which I liked very much, and talked about here. After reading Winnie-the-Pooh, I rather wonder why no one ever remembers his plays but everyone assumes they read Winnie-the-Pooh at some point. I think I've probably lost out by not reading it as a child, as it's definitely a children's book, rather than a book just about children. It succumbs to that occasional plague of children's books of being just a little bit patronizing, although it's not too bad here. I found Pooh stupider than I expected, and Eeyore far more depressing, and really I don't think I'd want to live with any of the animals. Despite all this, it's still rather a pleasant book, and even if I never actually read it as a child, I definitely watched all the films, so it's still got a firm place in my list of books crucial to childhood.