If little else the brain is an educational toy. While it may be a frustrating
plaything - one whose finer points recede just when you think you are mastering
them - it is nonetheless perpetually facinating, frequently surprising,
ocassionally rewarding, and it comes already assembled: you don't have to
put it together on christmas morning. The problem with possessing such an
engaging toy is that other people want to play with it, too. Sometimes they
rather play with yours than theirs. Or they object if you play with yours
in a different manner from the way they play with theirs. The result is,
a few games out of the toy department of possibilities are universially
and endlessly repeated. If you don't play some people's game they say that
you have lost your marbles. [Tom Robbins]