be in cloud-cuckoo land

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!
See also: land
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.
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