A crazy mixed-up day: Thirty brainteasers is one of eighty to ninety broadcasts for children that Walter Benjamin, one of the most influential of 20th-century thinkers, wrote and delivered over German radio from 1927 to early 1933. Transmitted between Radio Berlin and Radio Frankfurt, Benjamin’s broadcasts covered a fascinating array of topics. In this particular text, Benjamin proposes an intriguing and funny story about Heinz who is looking for the solution of a riddle. As we read along we need to find 15 mistakes and try to answer 15 questions. All solutions are presented in the end. Do you accept the challenge?