eye opener
1. An utterly shocking or startling thing, situation, or revelation. (Sometimes hyphenated.) The former champion's crushing defeat in the first round of the tournament was an eye opener to everyone who had expected her to make it to the finals without resistance. Learning about John's opium addiction was a real eye-opener for me.
2. A strong alcoholic beverage consumed early in the morning or first thing upon waking. (Sometimes hyphenated.) Primarily heard in US, Canada, South Africa. After going on quite a bender over the weekend, an eye opener was the only thing that could get me moving on Monday morning.