What does 1 Samuel 10:11 mean?

Everyone who knew Saul before saw him prophesying with the prophets and asked each other, 'What’s happened to the son of Kish? Is Saul now one of the prophets?' 1 Samuel 10:11 - Modern Text Bible

(People are shocked to see Saul acting like a prophet. It’s so unexpected that they wonder if he’s really the same person.)