[mannykannot]

The author was going somewhere when he began writing about what a developer is thinking about, but, perhaps because he was focused on vindicating TDD, he did not arrive there.

A developer who is writing unit tests must have a good idea of the purpose of the target of the tests, so she is thinking about requirements. Furthermore, if she is writing unit tests for small components (which will often be the case on account of everything being done in short cycles) then a lot of that purpose is contingent on other aspects of the design and how it is all supposed to work together: in other words, she is thinking about design.

If you don't spend some time thinking ahead about big-picture requirements and design issues, you are in danger of going a long way down a dead end.