When I was online with a company having to identify myself based on the questions when I signed up, and the rep on then phone said "here's one, if you get this right, I'll know you're you for sure. What's your favorite movie?"
(I remembered I had joined the legal research site and answered the security questions in the mid-1990s.)
I said "Breaking Away" -
she said "That's it, it's a really good movie, but in all my years here, it's never been anyone else's all-time favorite movie."