I don't know if you've driven in the East End of London recently, but I
assure you there those rules don't always apply!
The computers as cars metaphor is perfectly correct in many aspects:
1. You don't have to know how a car works to drive it: If everyone had to be
a qualified mechanic in order to drive safely then there'd be very few
drivers. Also, if everyone had to study car mechanics to drive nobody would
be able to study anything else. For the majority of people computers need to
be simple enough that anyone can use it without advanced knowledge. The
thought of teaching my mother to use a linux system makes me shudder.
2. Computers, like cars, need regular maintenance in order to function
properly: Cars need oil changes, computers need regular updates. With cars
there is a maintenance infrastructure to maintain them and, more
importantly, there is a basic understanding throughout the population about
what a car needs in order to function. When you have a problem with a car,
there's no shortage of people who have at least a basic understanding of
what to do. Plus everyone knows you can call a mechanic. Computers don't
have this infrastructure or basic permeated understanding yet, to most
people they are a magic box that flashes things on the screen-thingy. Most
have no idea that windows-update exists and wouldn't understand what it
does, and just as important doesn't know anyone who can tell them. Their
question is: what do I need to click on to fix it?
Greg