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.
(..) . . .and you will not mess it up. Harry Potter, such an honor it is. -Who are you? -Dobby, sir. Dobby the house-elf. Not to be rude or anything. . . . . .but this isn't a great time for me to have a house-elf in my bedroom. Yes, sir. Dobby understands. lt's just that Dobby (..)2002 Harry Potter and the Chamber of Secrets