The sequential math book in my junior year of high school. Because I wound up getting into a fight with the boyz in da hood on the bus on my way to school to return the book (they were not from my school). It didn’t help that it was the honors math book making me look like a total nerd, because there were only like 18 kids in that class and it was a mix of 10, 11 & 12th graders. For some time after getting off of the bus, while avoiding many blows from several people for quite some time, I had tucked my chin, as I had learned training in martial arts for the past two and a half years and held that two and a half inch thick book against my chin. At one point, one of them, who was directly in front of me, was actually able to hit that book with an extremely hard uppercut. There is no way he didn’t break his hand. No way. Because he screamed and grabbed his hand and they all froze. I then dropped the book and hit him the same way, sending him back about 10 feet into a garage door. And that was the end of it. They picked him up and left. Lots of fun. I still never understood why at least 10-15 of the kids who also got off of the crowded mining bus, ran away, when they had nothing to do with it and were not in any danger? Too bad there were no cell phones back then.