Karl Bushby, a former British paratrooper, embarked on an extraordinary journey in 1998 to walk an unbroken route around the world, a quest informed by his military upbringing and personal challenges. Raised in a military family—his father, Keith, served 24 years in the British Army's SAS, and his younger brother Adrian also pursued a military career—Bushby faced early hardships that shaped his resilience.

Throughout his childhood, Bushby struggled academically and socially. Undiagnosed dyslexia and the label of being “thick” made school a difficult environment, and he found refuge in birdwatching. At 16, he left school without formal qualifications and joined the Junior Parachute Company. Despite multiple failures during the physically demanding P Company selection, he eventually succeeded, impressing peers with his persistence, even though he remained somewhat isolated due to his refusal to engage in the army's prevalent drinking culture.

Bushby’s personal life was marked by separation from his son, Adam, following his divorce from his wife Angela. Stationed in Northern Ireland for several years, he was restricted from visiting Adam in Belfast due to military deployment rules. During this period, Bushby confronted a professional and existential crisis. The relative peacetime left him without the combat experience he had anticipated, while his lifelong sense of wanderlust grew stronger.

A turning point came in his mid-20s when a birthday card from his father sparked the idea of walking from London to New York via the Bering Strait. This concept soon expanded into an ambitious plan to traverse the globe on foot, running from the UK across Europe and Asia, crossing the Bering Strait into North America, and continuing all the way to the southern tip of South America. Bushby studied the geographic and logistical challenges, teaching himself subjects he had previously struggled with, including mathematics and physics, to prepare for the journey.

Mental health challenges also influenced Bushby’s decision. An avid long-distance runner, he suffered severe anxiety when missing training, at one point seeking help from a behavioral psychologist. Confronting his own mortality, he felt compelled to pursue a meaningful, unprecedented endeavour despite the personal sacrifices, including years away from his son.

On November 1, 1998, Bushby began his expedition from Punta Arenas, Chile, after traveling to the Falkland Islands aboard an RAF flight. Armed with $500 and a basic supply kit, he faced hostile conditions immediately on the Patagonian steppe. Violent winds, freezing temperatures, altitude sickness, and starvation tested his limits. Recognizing the dangers, he altered his route to cross the Andes Mountains, where he encountered both severe hardship and unexpected generosity.

Throughout his travels, Bushby’s perception of humanity shifted. Despite initially harboring a cynical view from his years in the military, he found warmth and kindness among the people he met in often remote and impoverished communities. Local families and strangers provided food, shelter, and support, sometimes going to great lengths to assist him. One notable act of kindness included a stranger who delivered substantial food vouchers and money, in exchange for the simple favor of delivering a postcard years later.

In 2000, while in Peru, Bushby suffered a serious illness involving multiple infections. Once again, the generosity of strangers proved crucial: a doctor and her family cared for him for a week, providing treatment free of charge and helping him recover.

Bushby credits these experiences with redefining his understanding of humanity and reinforcing his commitment to completing the unprecedented journey, which has continued over more than two decades.