Thirty-five years since the publication of Fischhoff’s (1975) seminal article, we continue to be fascinated by the hindsight bias. Like a well-developed character in a novel, the bias has something for everyone. Its basic tenet – that things seem less surprising in hindsight than they should – is instantly recognizable as a common human flaw. It is robust, often difficult to reduce, and appeals to researchers with a wide range of interests including history, business, law, medicine, and of course, psychology. This interest stems from the belief that failure to be surprised by an event prevents us from learning from it, and will likely cause us to judge others unfairly for not having been able to foresee it. But just how bad is it? Although guided by a cold cognitive mechanism that ‘creeps up’ on us, hindsight bias is complex, seemingly strengthened, and yet also reduced by self-serving motives. In this article, I introduce the reader to the basic designs used to study the bias, key cognitive and motivational mechanisms, the major controversies, and some unstudied questions that I hope will guide future research.