There is a scene in the movie Drinking Buddies where Gene and Luke are talking in a bar.
Gene: I've been ten minutes out since I got here. I had one of these, and then I said, "I'm gonna have one of those," and then here I am.
Luke: Yeah, it's hard once it starts going in.
Gene: I don't know what I am. Four or five in?
Luke: You're five in?
Gene: I might've.
Gene: But I had a turkey burger earlier, so...
Luke: You're really keeping it together.
Gene: Yeah, I'm a quiet drunk.
What does it mean to say someone is four in? That person has drunk four beers? So if I have had three cups of coffee, can I say I am three in.?