Her dream of competing in the Olympics became a 'reality'. [=she competed in the Olympics, as she had dreamed of doing]
He was starting to think he was infallible, so the criticism from his boss served as a 'reality check'.
Her friends gave her a 'reality check' about her boyfriend. [=told her the truth about her boyfriend]
(..) ...you dump him in the marsh. Not where some guy from John Hancock goes every Thursday... ...to get a fucking blowjob! Don't laugh! This ain't reality TV! Proceed. - What? - Yeah. You got a tail. Two cars. Not very subtle. (..)2006 The Departed