Idioms are used all the time and unless you recognize when an idiom is being used, what you read or hear ______ can easily be misunderstood 

--- Would you mind if I closed the door ? --- ___________．The wind is blowing strongly．

Sarah hopes to become a friend of _____________ shares her interests.

You can't wear a blue jacket _____ that shirt — it'll look terrible. 

I firmly believe _____ he said at the meeting was right.