This article reinvestigates German and British soldiers’ impressive resilience during the First World War. Rather than following previous historiography’s societal and military-institutional approaches, it focuses on combatants’ psychology. Men coped overwhelmingly successfully by failing to recognise fully the front’s disempowering and dangerous nature. Fears were repressed or minimized with black humour. Through religion and superstition, imagined order was imposed on the chaotic environment, while optimistic reasoning and exaggerated faith in personal control encouraged individuals to overestimate their survival chances. These ‘positive illusions’ protected men from unnecessary strain, sustained combat motivation and may even have raised life expectancy at the front.