Everyone has one. The moment that you click and realise, no matter how pervasive technology has become, no matter how technology-adjusted you think the person is, you click and realise that most people just don't think in the same way. An enlightenment, if you will.

Mine came over dinner with my sister tonight. She was trying to arrange a home stereo system similar to the one my father has set up, and asked what the 'box of songs' was. I stared blankly at her, not comprehending: had dad bought a networked MP3 player? An iPod just hooked up to the stereo?

To my sister, a 'box of songs' is a huge IDE disk hooked up via USB mass storage. That I don't expect her to understand, but to her, it's not a portable hard drive, because that's not what it does. It's just a big box of songs.