Karl investigates how people should spend their limited time on the planet as he finds out what he will be like as an old man.

As Karl explores the impact of waste on our planet, he meets a roadkill chef, as well as a man who has found a unique use for old bottles.

Karl investigates the alleged benefits of urine therapy as he explores the lengths people go to in order to stay healthy.

Karl meets a group of vigilante superheroes in San Diego as he goes in search of people with unique attitudes towards life.

Karl continues to investigate life's big questions by explores the key factors that shape our people's identities, including gender, accents, hair and clothes, He heads to Los Angeles where he goes for a stroll on Newport beach dressed as a woman, before travelling to Atlanta to meet a man who has made a business out of putting hair back onto the heads of bald men. Karl's journey also takes him to Las Vegas, where he speaks to those who make a living out of looking like celebrities.

Karl Pilkington goes back on the road in search of the answers to more of life's big questions, beginning by heading to America to consider the point of art. He meets artists who make sculptures out of dog muck, attempts to create a masterpiece from his own vomit and strips down to his pants for a spot of performance art in Times Square.