FTA: > Thus, every program had to be learned individually and its complete user interface memorized. It was a sign of expertise to have learned the UIs of doze

FTA: > Thus, every program had to be learned individually and its complete user interface memorized. It was a sign of expertise to have learned the UIs of dozens of applications, since a novice user facing a new program would find their existing knowledge of a similar application absolutely no use whatsoever. Hello, web, looking at you. Except that no UI is stable long enough that people ever bother mastering it.