Meaning
- used to describe a stupid person.
- refers to a person who is not very bright.
- a daydreamer.
- a person whose mind is elsewhere
- an otherwise intelligent person who is not using their brain.
- someone who is not at all alert.
- something that you say when you think someone is stupid.
- when someone does not react because they are thinking about something else.
- have a brain, but not using it.
- used to tell that someone lacks cleverness or alertness.
Example Sentence
- No matter how hard I try to understand what Jim is talking about, it is apparent that his lights are on but nobody is home.
- Because her lights are on but nobody is home, she has no idea what the group has decided.
- The team is trying to get Mark to provide his input, but he is unable to do so because his lights are on but nobody's home.
- I tried to understand him, but the lights are on but nobody is home.
- John has no idea about this - the lights are on but nobody's home.
- Lilly studied interior design, but the lights are on and nobody is home.
Origin
Originated in America, people have been using this idiom since at least the 1970s. The phrase first appeared in print in 1974, in Jason A. Colquitt's book Organizational Behavior.
If you were to take this phrase literally, it would mean that you are looking at a building that has all of its lights switched on. Because of this, it would be logical to assume that the property is occupied or otherwise in use. In reality, it is empty and void of any action. This has been taken to describe a person who may be standing right in front of you, but whose mind is somewhere else. You can be looking right at them and have it appear that their lights are fully switched on, only to discover that they have no clue what is going on around them.
While no one person is coined with coming up with this idiom, it appears to have developed in response to a growing number of people starting to become aloof when being spoken to. People noticed that certain individuals seemed to be a lot slower than normal when listening to and responding to the most basic of conversations. Even though they were physically present, their mind would obviously be elsewhere. This idiom also refers to a person who has the habit of not paying attention when being spoken to.