Almost every popular commercial product owes its success to two different qualities. First, it does the job it is ostensibly designed to do pretty well. Secondly, it has some quality that you might call ‘limbic appeal’. It delights or soothes our unconscious mind in ways which defy objective measurement.

Much as it delusionally believes that it runs the show, the power granted to conscious reasoning within the brain is that given to a slightly colour-blind, utilitarian man when he buys a sofa with his wife.