On "Seinfeld," Frank Costanza famously shouts "Serenity now!" after learning the phrase from a relaxation tape.
In season 9's "The Serenity Now," an instructional tape tells Frank to repeat the phrase whenever he becomes angry, supposedly to help lower his blood pressure. Frank adopts the advice with his usual intensity, shouting the words rather than calmly using them. His son George also begins using the mantra while working in telemarketing, but the phrase merely suppresses anger until the emotions eventually burst out.
The episode treats "serenity now" as an ironic slogan: the words promise peace, while Frank, George, Jerry, and Kramer become increasingly volatile. Kramer eventually uses the phrase before smashing George's computers, demonstrating the danger of confusing emotional repression with genuine calm. The episode aired on October 9, 1997, as the third episode of season 9. Writer Steve Koren based the idea on hearing his own father use the phrase during a rage-control exercise.