Humble Pi A Comedy of Maths Errors

Probably in the course of following Matt Parker and being generally interested in the same stuff as him, I'd come across a solid 60-70% of the book's contents beforehand. It was still presented in a fun way, and the lessons and takeaways from the various stories were well-presented. I especially liked the shout-out to Canadian engineers at the end, and the level of humor was well-balanced with interesting new content.