That quotation is in fact from "Wind, Sand, and Stars", the memoir of the same author.

On the same theme:

> the supreme goal of all theory is to make the irreducible basic elements as simple and as few as possible without having to surrender the adequate representation of a single datum of experience

- Einstein

> I would have written a shorter letter, but did not have the time

- Pascal

> Simplicity is a great virtue but requires hard work to achieve and education to appreciate, and, to make matters worse, complexity sells better.

- Dijkstra.