My last year of college. I lived with 3 of my best friends in a house and the youngest dude turned 21 in October. From that point onward we drank pretty heavily until one night I got so hammered I blacked out I knocked my now fiance over, pissed in the corner of my room, tried to fight the biggest guy in the room, and almost got put in the hospital when the guy shoved me and I hit my head on a bench. Also managed to call a few of my ex's.
It was an awful experience. Normally I'm a pretty calm and level headed guy and dealing with the aftermath was humiliating, expensive, and both emotional and physically painful.
Let's just say I know my limit now.