be in cloud-cuckoo land

To believe in or be absorbed by unrealistic, idealized, and/or fanciful ideas that are beyond the realms of possibility. If Tom thinks he'll be able to live off his bad poetry, he's in cloud-cuckoo land!

Common Names:

Name	Pronounced	Usage
Harris	['hæris]
Gwillym	-	Welsh
Hodei	-	Basque
Bedisa	-	Georgian
Leopoldo	le-o-POL-do (Spanish)	Italian, Spanish, Portuguese
RosalÍA	-	Spanish, Galician