Meaning – La-la land is an imaginary place where people are out of touch with reality. It is a hypothetical place that you visit when you are not paying attention or you are daydreaming. If you are in la-la land you are zoned out (lacking concentration) or in a state of semi-consciousness. You are disconnected from reality.
This phrase can also be used to call-out or challenge someone who is making ridiculous claims. A person would have to be living in la-la land to believe such nonsense.
There are a number of expressions with similar meanings – all used to bring attention to a person’s lack of concentration or daydreaming:
away with the fairies – That boy is away with the fairies.
cloud cuckoo land – You must be living in cloud cuckoo land!
head in the clouds – She’s always had her head in the clouds.
out to lunch – That’s crazy. You are totally out to lunch.
scatterbrain – I’ve done it again! I’m such a scatterbrain.
space cadet – I forgot again! I’m such a space cadet.
La-La land is also sometimes used as a nickname for Los-Angeles or Hollywood.
“I do worry about Peter sometimes. I try and have a conversation with him but he’s away in la-la land!”