They said, “Look at the contrast—here’s Norvig’s Sudoku thing and then there’s this other guy, whose name I’ve forgotten, one of these test-driven design gurus. He starts off and he says, “Well, I’m going to do Sudoku and I’m going to have this class and first thing I’m going to do is write a bunch of tests.” But then he

never got anywhere. He had five different blog posts and in each one he wrote a little bit more and wrote lots of tests but he never got anything working because he didn’t know how to solve the problem...

Xeno's Paradox: Divide-and-Conquer only works if you actually do some conquering.