We can learn what we don't understand. To use a current example, in modern user interfaces there are two types of metaphors: the ones you can deduce by looking

We can learn what we don't understand. To use a current example, in modern user interfaces there are two types of metaphors: the ones you can deduce by looking at them (a push button affords to be pushed) and the ones you learn (clicking underlined words was not obvious not so long ago).