Final answer:
Paul's feelings would have been a mix of fear and excitement influenced by societal beliefs on the nobility of war, contrasted by the later revealed horrors and absurdity of trench warfare causing deep trauma.
Step-by-step explanation:
In the film All Quiet on the Western Front, Paul's feelings as he prepared to board the train for the front lines would likely have been a mixture of apprehension, fear, and indoctrinated excitement. The early stages of World War I, as depicted in the image of German soldiers in a railway supply train on the way to the front in 1914, often showed young men unaware of the realities they were about to face.
The societal belief at the time was that war was noble and that there would be a quick victory. However, the literature after the conflict, like Remarque's work, Hemingway's A Farewell to Arms, and others, revealed a far different experience that included the horror and absurdity of trench warfare and the trauma it caused, often leading to PTSD, then known as shell-shock.