Where your cups at?

I'd like to, if I may be so bold, call the re-emergence of a new language meme (I'm sure, no doubt, that many of you will tell me that it never really went away.)

I refer to the phrase in my cups. Urban Dictionary provides a definition.

Now, I say this because I've read/heard it in three different works recently:

Frank McGuinness' Greta Garbo Came To Donegal
Peter Carey's Parrot and Olivier in America
Hans Fallada's Alone in Berlin.

What's really intriguing here is the fact that these three works are located in such different spaces and times (late 60s Ireland, 19th century America, 1940s Germany) and yet, there the phrase is, meaning exactly the same. (An additional layer of complexity is the fact that I'm reading the Fallada in a translation from the German by Michael Hoffman.)

I haven't been able to turn up much on the etymology of the phrase, so I'd be intrigued if anyone has any clues. I guess that Bill Shakespeare will probably be involved...

And do you, dear reader, still use it? Straight up? Ironically? When sober? Do tell.