John Steel 'Jock' Lewes was born in Calcutta, India, where his father worked. His early life was marked by a privileged upbringing within the British colonial setting.

Living in India exposed Lewes to diverse cultures and likely instilled in him a sense of adventure and adaptability, qualities that would serve him well later in life. Specific details of his daily life during this period are scarce, but the environment undoubtedly influenced his worldview.

Lewes attended a prestigious boarding school in England (likely Ampleforth College, though confirmation requires further research), following the typical path for upper-class British children. This would have instilled discipline, teamwork, and a sense of patriotism.

Lewes attended Brasenose College, Oxford, where he studied Philosophy, Politics, and Economics (PPE). This rigorous academic program honed his critical thinking, analytical skills, and understanding of global affairs. He was a keen rower, demonstrating his physical fitness and competitive spirit.

Lewes excelled in boxing during his time at Oxford, showcasing his physical strength, agility, and determination. This athleticism would prove invaluable in his later military career, especially during commando operations.