In anticipation of the forthcoming movies, I've been re-reading The Chronicles of Narnia, the beautiful series C.S. Lewis wrote following World War II. I first read all seven books in 4th grade, and I'm now reading them again in that same order - the order in which they were originally written, not the chronological re-order that modern publishers insist upon.
Re-reading childhood stories has a two-fold power for me. There's the nostalgic layer: I rediscover the excitement I felt when I first read the books; I'm reminded of moments when I empathized strongly with certain characters, tough spots in the narrative that I didn't understand. And I've discovered that the mental images and maps I made of the people and lands that Lewis describes have remained unchanged for the 18 years.
At the same time, there's the meta layer: my adult self gets to analyze the flow of the story, consider the author's writing style and technique (I had no English degree in 4th grade - each book paints a truly rich narrative in a short space), hunt for the Christian symbolism, and consider the challenges of writing for children.
Most impressively, it's a privilege to look back and understand why 9-year-old me loved the books, why I was drawn to certain parts of the stories more than others, and what made reading a treat for me as a boy. I still laugh at the samelines of dialogue, still like certain passages the best.