When you drink mass amounts of liquor quickly, and you feel the same until 15 minutes later when it crushes yo' face. Hence, the liquor metaphorically punches you right in the face.
Drinker: Yo, I just chugged 99 bananas and I don't feel a thing.
Boozehound: Wait till you get punched in the face so hard!
A sardonic, informal term used to address an obnoxious person. Especially one who often says things to unfairly upset or demean others. It is based on the premise that because people have always chosen to physically restrain themselves around the person in question, they've never had to stop, reconsider and change their offensive behavior.