Mikhail Khodorkovsky

Fortunes are made, and disappear, over the lifetime of a single generation. Today, a person in essence takes his wealth from society just for the duration of his or her lifetime. The next generation has to create it anew.

I can well imagine that certain writers, even writers that we'd consider today very great writers, may not necessarily have tested highly on IQ just because of their numerical skills, or maybe they may not be very good at memory, and are not particularly good at these kinds of tests.