The Novel That Is Not About What You Think It Is About

I came to It expecting a horror novel about a supernatural clown. What I found was a novel about seven children in a small Maine town who face something they cannot name or explain, and who grow up and have to go back. The horror is real and often genuinely frightening. But the central subject of the book is memory: how what happened to you in childhood shapes everything that comes after, and what it costs to return to the place where it happened.