The author of the brilliant best-selling book - The Life-Changing Magic of Not Giving a F**k.

I keep seeing people reading this book all over London. It's been a huge hit for Sarah. The interview contained such amusing parts as the four categories of potential F*** giving. Then she wrote the book - Get Your Sh*t Together: How to stop worrying about what you should do so you can finish what you need to do and start doing what you want to do. Now she's moved to the Dominican Republic, recorded a viral Tedx talk, and had a crazy Zestology-inspired coincidence. All of which is good podcast topic material.

Potty-mouthed Sarah Knight specialises in best-selling books with vaguely naughty words in the title. And she's decidedly anti-guru. She's perfect for Zestology.