I am a VP at a medium size company and I do plenty of interviews. I usually talk about what people are interested in and then ask one question:

"You are in front of PC/Mac/Mobile screen, type www.cnn.com into browser, and press enter. A fraction of a second images show up on the screen... How? What happened? Tell me all you can from key press interrupts to underwater fiber cables".

This question never failed me. It always shows how deep does one go in their computer science adventures.

Wow. What a great question! I found that I was sitting here answering it to myself. After starting down a rabbit-hole on how the browser would probably need to do some GPU initialization, I realized how much fun I'd have talking through this with someone in an interview.

"Let's see, I guess the wifi radio is going to have to do an RSSI measurement..."

It actually gave me goosebumps when I realized that I was so caught up in it and how excited I was getting.