“When you say that someone is in la-la land, what you mean is that they are out of touch with reality. The person has no clue what’s going on”.
For example, “I have no idea what’s going on with my cousin Ganesh. He seems to be in la-la land.”
“If you ask me, people who believe that cricket is still a gentleman’s game are living in la-la land.”
Where does the expression ‘la-la-land’ come from?”
‘LA’ is the short form of Los Angeles. People living in this city are thought to be odd or eccentric. Hence the expression ‘la-la land’.
Source: “The Hindu” – Know Your English Column – March 04, 2008