Identity has been causing problems for centuries. It has enabled exclusion, political manipulation, oppression, ethnic cleansing, and even genocide. These unintended consequences, mistakes, or miscalculations can have a major impact. And as the world is rushing towards a far more digital society in the wake of the global pandemic the scale of such mistakes could be catastrophic. By learning from the past, we can better address the problems facing us today. Failure can often be a great teacher so here we will examine a few choice moments in history and how they can help us build better identity systems in the future.