>To think that things that are completely impossible might happen, rather than understanding how things really are.
>A realm of fantasy or of whimsical (means, unusual, playful, and unpredictable, rather than serious and practical) or foolish behavior
>An idealized, illusory domain of imagination
Example
>When referees make contentious decisions players are going to be upset, and anyone who thinks otherwise is living in cloud cuckoo land
>Anyone who believes that the a fake activist will be effective is living in cloud cuckoo land