Before all the laws of software, before the purpose of software, before the science of software design itself, there is a singular fact that determines the success or failure of a software developer. This fact makes the difference between the senior engineer who can seem to pick up new languages in a day and the junior developer who struggles for ten years just to get a paycheck, programming other people’s designs and never improving enough to get a promotion. It differentiates the poor programmers from the good ones, the good programmers from the great ones, and the great ones from the...