If a theme or idea is too near the surface, the novel becomes simply a tract illustrating an idea.

There are signs that the age of petroleum has passed its zenith. Adjusted for inflation, a barrel of crude oil now sells for three times its long-run average. The large western oil companies, which cartellised the industry for much of the 20th century, are now selling more oil than they find, and are thus in the throes of liquidation.

So Harry Potter came in and it is nice that I have kids of the right age. I took them to London and they walked around the set and met Harry Potter and that is thrilling.