From Longman Dictionary of Contemporary Englishrude awakening/shockrude awakening/shockREALIZEa situation in which you suddenly realize something unpleasant If they expect the match to be friendly, they’re in for a rude awakening. → rude
Examples from the Corpus
rude awakening/shock• But shopping for food in Miyako brought a rude shock.• But, come the morning, Ronni was in for a rude awakening.• Conservative elements steeped in uniformitarian philosophy cannot be expected to welcome such a rude awakening.• The case has gone against the Pings, but it was a rude shock in a world of gentlemen.• Renters who move into a vacated apartment face the rude awakening of the market rate an owner is permitted to charge.• This rude awakening was, however, still a few years away at the time when Dustin joined.• The only good thing about his rude awakening was the discovery of a gigantic hedgehog behind one of the goalposts. 