Definition
Describes a state where someone is absorbed in their own thoughts or fantasies, not paying much attention to what is happening around them; detached from reality.
He's always in a world of his own, making it difficult to have an in-depth conversation with him.
During the meeting, she seemed absent-minded, as if she was in a world of her own.
Since moving to the countryside, he seems to live in a world of his own and rarely interacts with people.