Beautiful article about interfaces. One of the lines that stuck was:
All maps are lies. Useful lies, but lies all the same. They don’t tell you everything about the territory. If they did, they’d be totally useless and impossible to read. Maps show you a highly simplified model of the territory—an incomplete version of the truth based on your goals, context, zoom level, location, etc. They’re helpful because they leave stuff out.
That is so much true about applications. Good applications are like maps. "They're helpful because the leave stuff out." They make things simple.