"Drei Gläser" = Three glasses
The famous scene is from Inglorious Basterds, where Major Hellstrom sees the British version of a "3" confirming his suspicions that Hicox (Michael Fassbender) and co. are impersonating German officers.
Share your stories of this happening in your job / hobbies / endeavors
good question. I don't think I've had such a moment yet. All my truths have been revealed to me slowly over time. Never all at once in a particular moment