David Kundtz has enjoyed several careers, including eighteen years in religious ministry and twenty years in the practice of psychotherapy, public speaking on stress and emotional health, and writing. He has graduate degrees in psychology and theology and a doctorate in pastoral psychology. Among the books he has authored are Quiet Mind, Moments in Between, and Awakened Mind.

During his life, Richard Carlson, PhD, was considered one of the foremost experts in happiness and stress reduction in the United States and around the world and was a frequent featured guest on such shows as Oprah, The Today Show, The View, NNC, CNN, Fox, PBS and over 2000 other shows. Don't Sweat the Small Stuff continued to be a publishing phenomenon with over 20 titles in the brand franchise, two of which were coauthored with his beloved wife, Kris. He died of a pulmonary embolism in December 2006, at the age of forty-five.

The words "Don't Sweat the Small Stuff" have become a part of American Culture thanks to Richard Carlson's book that became a runaway bestseller and made publishing history as the #1 best-selling book in the United States for two consecutive years. Don't Sweat the Small Stuff spent over 100 weeks on the New York Times Bestseller list and is still considered one of the fastest selling books of all time and has sold over 15 million copies worldwide.