In a world of your own refers to a state of being preoccupied or lost in one's own thoughts, disconnected from the external world. There are several synonyms for this expression, including "zoned out," "daydreaming," "lost in thought," "not paying attention," "absent-minded," and "deep in contemplation." These synonyms all highlight the same mental state of being disengaged from one's surroundings and lost in one's thoughts. Whether you are lost in thought about a specific topic or simply enjoying your own company, being in a world of your own can be a peaceful and enjoyable experience.