I just finished reading Stumbling on Happiness, and I highly recommend it. The material it covers overlaps a lot with the Positivity topics covered in the Usual Error presentations, and it goes into a lot more detail. It’s a whole book on positivity instead of just one presentation! If you’re interested in knowing how to live a happier life, or just curious about how your brain plays tricks on you that influence your happiness, then give Stumbling on Happiness a read.