why is darry so worried when ponyboy tells him he had a dream the night before

Ponyboy tells Darry that he had "one of those dreams last night. The one I can't ever remember." He had the same dream the night of his parents' funeral, and "woke up screaming bloody murder" but unable to remember what it was about. The dream started reoccurring, so Soda started sleeping with Ponyboy. Two-Bit asks him if it was very bad, but Ponyboy lies and says it wasn't.