Avoir le cafard- I am bored.
However, literally this phrase means ‘to have a cockroach’!

Coup de foudre- Love at first sight.
However, literally this phrase means ‘a flash of lightening’.

Devenir chèvre- to become very angry.
Literally this phrase means ‘to become a goat’!

Revenons à nos moutons-Let’s get back to the topic.
Literally this phrase translates as ‘let’s return to our sheep’!

Du jour au lendemain- Something happened suddenly and unexpectedly. However, literally this translates as ‘from the day to the next’.