never-never land

劍橋詞典

an imaginary place where everything is pleasant or perfect in a way that is impossible to achieve in real life
世外桃源，理想樂土
If he thinks we can get this done by next week , he's living in never-never land . 如果他認為我們下周就能把這項工作完成的話，那他簡直是在妄想。 返回 never-never land