Just FYI, when I was a kid, I memorized all four stanzas of The Star-Spangled Banner. I was inspired by an Isaac Asimov mystery in which a German spy posing as an American is caught because the interrogator plays the game of "You say the first thing that comes to mind" with him. The interrogator says, "the terror of flight," and the spy comes back with "gloom of the grave."

As the interrogator pointed out, only a spy would have studied the national anthem so intently, so he wouldn't be caught not knowing it.