H.P. Lovecraft understood something fundamental about fear: the unknown is often more powerful than the known.
Once a mystery is explained, it becomes manageable. Once a monster is fully understood, it becomes a problem to solve.
Horror lives in the space before the explanation arrives.
It lives in unanswered questions, half-glimpsed shapes, and the uneasy suspicion that reality may be far stranger than we imagine.
As a writer, that is what fascinates me most about the genre. Not the monster itself, but the moment when a character realizes that the world is larger, older, and more mysterious than they ever believed.