In the beginning, nobody knew how to use an iPhone . That informed everything about the device's design: The green felt in Game Center communicated fun and gambling, the messily ripped paper at the top of the Notes app made clear that this was where you scribbled away. The music app was called iPod, not Music, because Apple deemed that more easily understood. Using an iPhone was like bowling with bumpers—no one told you exactly what to do, but you couldn't screw up too badly either.