Embracing Nihilism as a Software Development Philosophy and the Birth of the Big Book of Dead Code

Agile software practitioners often brag about how quickly they can change course with a project as the requirements evolve and change. What happens to the things we no longer need? Are projects removing functionality no longer needed by the project? Are we truly willing to abandon or even (gasp! delete) "dead" code. Do we know dead code when we see it? Even the most agile developer has left unnecessary code because it "might" be used in the future. Even the most agile product manager has left a seemingly useless feature because "someone" might want it.