Interviewing for Google: What would your answer to "the hard question" be?

From Jason Kottke: In the early days of Google, Sergey Brin ended his job interviews in an unusual manner.

Finally, he leaned forward and fired his best shot, what he came to call ‘the hard question.’

”I’m going to give you five minutes,” he told me. “When I come back, I want you to explain to me something complicated that I don’t already know.” He then rolled out of the room toward the snack area. I looked at Cindy. “He’s very curious about everything,” she told me. “You can talk about a hobby, something technical, whatever you want. Just make sure it’s something you really understand well.
— http://www.wsj.com/articles/SB10001424052702304911104576444363668512764

So I challenged myself to come up with a few of the complicated subjects to which I have expertise that I might have used in an interview with Brin.

They are:

  1. Successfully attend and graduate from a woman’s college as a man
  2. Schedule 60-100 employees of varying skill levels, while accounting for specific financial and scheduling needs and language barriers, for work at a 24-hour fast food restaurant, while also being held accountable for labor cost as a percentage of actual sales based upon uncertain and consistently inaccurate sales projections
  3. Planning for and executing 27 effective parent-teacher conferences during a 3-5 day period
  4. Playing consistently profitable poker
  5. Crafting and telling a winning story at a Moth StorySLAM

What would your answer be?