One of the beautiful things about great UI is that it's
not there. [....] It's like a guitar player who just lets
the music come out and they're not really sure if the
guitar's there any more.
It takes sustained time and effort to learn to play guitar, or to learn to touch-type, or to program, or to manipulate programs in a code editor. This is a completely different use case from that of a casual web site user. You don't hand a musician a 5 inch screen with a big blue button and expect them to play it like a guitar.
