'Live rent free' This is an English slang expression that is often misunderstood. This expression actually means to be constantly thinking about something, or someone. For example; 'That song from Tiktok has been living rent free in my head all day' 'My ex boyfriend still lives rent free in my head' 'After seeing that new film, the idea of moving abroad lives rent free in my head' Surprisingly, it has nothing to do with rent, bills or money! Can you think of another way to use this expression?