The communications theorist Marshall McLuhan observed that "we look at the present through a rear-view mirror." And that "we march backwards into the future." Amen. Remember the horseless carriage? Not to mention the fact that we still measure the oomph of a Porsche 911 in, er, brake horsepower.

But the car industry is a ferment of modernism compared with the computer business. When the bitmapped screen and the Wimp (windows, icons, menus, pointer) interface first surfaced in the early 1970s at Xerox Parc, its geeks searched for a metaphor that would make this new way of relating to computers intelligible to human beings. So they came up with the "desktop" on which were displayed little images (icons) of documents and document folders, just like you'd find on an actual desktop. Well, on the desktop of an efficient bureaucrat anyway.

But then they ruined everything by putting a trash can on the desktop. And Bill Gates & Co compounded the offence when they released Windows 95, which also had a start button on the desktop. The result was that, for a time, when most of the world's computer users wanted to switch off their machines they had to press start. Even the car industry thought that was weird.