If you think this job is going to be easy, you're in for a 'rude shock'. [=you will be unpleasantly shocked when you find out that this job is not easy at all]
He's about to have a 'rude awakening'. [=he's about to find out something that will shock him unpleasantly]
I was 'rudely' [=suddenly and unpleasantly] awakened from my nap.
(..) Wanna check something. - Where's Harry? - He's probably on the platform. Come on. Didn't Mummy ever tell you it was rude to eavesdrop, Potter? Petrificus Totalus! Oh yeah... She was dead before you could wipe the drool off your chin. That's for my father. (..)2009 Harry Potter and the Half-Blood Prince