During one scene a perpetual calendar is visible. It's a 26^th.

– Why do they call you The Gorilla? – Because I'm big and strong… and everyone has to have a name.

Mr R. (Kurt Raab), his full name is irrelevant, is a hardworking, almost invisible man. He laughs along when his coworkers make stale jokes to shorten the long days. He neatly completes his draftman's assignments and politely nods when the boss berates him. He smokes too much, 80 a day, and at the yearly checkup is told to cut the habit down. His son fails at school and Mrs R. wishes for nicer furniture and a skiing holiday, when Mr R. is promoted.

“No, no, geh' nicht vorbei, als wär' nichts gescheh'n, Es ist zu spät, um zu lügen, Komm und verzeih, ich werd' mit dir geh'n, Wohin dein Weg auch führt, Und die Welt, sie wird schön.”

– Christian Anders, Geh nicht vorbei (1969)

So why does Herr R run amok?