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.
(..) of pity me # # Yeah # # It's been a long night chasing ghosts # # But at the most # # It's been a rude awakening # # That all too late I finally see # # I finally see # # I see that it's # # My loss # (..)2002 Sweet Home Alabama