Zach Galifianakis revealed on Conan O'Brien's last night show why he recently quit drinking.

See the clip here:

The actor told a story on Wednesday night's taping of Conan about a night when he was walking down a street on the Lower East Side of Manhattan. He had had several shots of whiskey and was on his way home when two men in a Jaguar cut him off when he was crossing the street.

Galifianakis, in his drunken state, was angry with the men and struck the Jaguar with his hand. As he continued walking, he saw the two men get out of the car and they both proceeded to spit in his face. He decided then that he would give up drinking.

The actor joked with O'Brien, rhetorically asking, "I don't know if you've ever been spit in your face non-sexually."

O'Brien noted that the Galifianakis had visibly lost a lot of weight, to which the actor cited the lack of drinking as the main reason.

He went on to tell O'Brien how he feels about being recognized in public. He said that he doesn't enjoy it, explaining, "I'm kind of private . . . it's a tricky thing, to be noticed." He joked that if a pack of teenagers ever come his way he usually runs in the opposite direction.

Ironically, Galifianakis rose to fame for his scene-stealing role in 2009's The Hangover, a comedy film about a group of friends who struggle to remember the events of a wild, drunken night in Vegas. The film's runaway box office success led to an equally successful sequel in 2011.

The actor is back again for The Hangover Part III, which is set to be released on May 23rd. Galifianakis plays the socially inept Alan alongside Bradley Cooper's Phil, Ed Helms' Stu, and Justin Bartha's Doug.

Galifianakis hosted Saturday Night Live for the third time on May 4th.

Tags: zach galifinakis Conan O'Brien the hangover