I bought a self-help book on how to stop worrying.

This joke brilliantly plays on irony and a touch of absurdity. We're conditioned to expect self-help books to be filled with extensive advice, strategies, and perhaps even homework to tackle our problems. The setup primes us for a long journey of introspection and effort to overcome worry. However, the punchline delivers the exact opposite: a complete lack of content. The humor stems from the unexpected and ridiculously simple "solution" – if there's nothing to read, there's nothing to worry about, thus achieving the book's stated goal in the most minimalist way possible.

Self-help literature has a long history, with books offering guidance on everything from personal finance to emotional well-being becoming incredibly popular in the 20th and 21st centuries. Many people genuinely seek these resources to navigate life's complexities, including the pervasive issue of worrying. This joke subtly pokes fun at the often overwhelming nature of advice, suggesting that sometimes the most effective way to stop worrying isn't through complex strategies, but by simply letting go of the need for an elaborate solution, much like the blank chapter encourages.