After graduating from Oxford, Lewes worked in marketing or sales, gaining experience in business and interpersonal skills. While the exact details of his employment are not widely documented, it indicates an interest in practical application of his education and a desire for professional independence.

Details of his pre-war activities beyond his professional life are somewhat limited. However, it's likely he engaged in social activities typical of his social class and may have shown an interest in current affairs, given his education and the growing tensions in Europe.