Dic: a rude awakening

• We had a rude awakening when we saw the amount of our phone bill.
• You've been so spoiled by your parents, you are in for a rude awakening when you start to look after yourself.

2. PHRASE | If you have a rude awakening, you are suddenly made aware of an unpleasant fact.

.... http://idioms.thefreedictionary.com/Rude, Cobuild