As a connoisseur of fine mistakes, I was happy to find Matt Parker’s book. I knew him from YouTube where he broadcasts the same type of content. He is a mathematics teacher and comedian, and I thought this book was about as good as something like this can be. I can’t tell you too much about it or it would spoil all the great mistakes (although there are a few that you’ve probably heard of), but I was entertained to hear that the German police were searching for a serial killer for years. Her DNA turned up at every crime scene. They eventually learned that the DNA belonged to a woman who worked at the factory that made the cotton swabs they were using.