一日一成语【205】the lights are on but nobody’s home 心不在焉

the lights are on but nobody’s home
[俚]心不在焉

Because the lights are on but nobody’s home, she cannot understand what the teacher is saying.
因为她心不在焉，所以根本不懂老师在说什么。

注解：
light意指灯，on意指亮着的，开着的，nobody意指没有人，home意指在家；the lights are on but nobody’s home系指家里灯亮着但没有在家，喻指心不在焉，身在曹营心在汉。