I don't think I agree with calling that question "simple". I could probably speak non-stop an entire hour before we even leave my local computer: electric impulses, protocol between keyboard and PC, BIOS, interruptions, ASCII and Unicode, OS, cache, types of local storage, CPU, GPU, window management and TCP stack, encryption... It's hard to come up with a computer-related field that's not somehow involved in answering that one question.

If anything, I always consider it a good question to assert whether someone knows when to stop talking.