For some reason, people in a swaying vehicle easily feel drowsy.
Some scientists say this is because the frequency of the vehicle's body or tire vibrations aligns with a switch in the human body, amplifying people's fatigue and causing drowsiness.
Other scientists say that the gentle bumpy swaying is like a childhood cradle, forming a long-conditioned reflex in the subconscious, inducing sleepiness.
But whether they are right or not, regardless of the reason, many of the soldiers began to feel sleepy.
Life in the trenches always made it difficult to sleep, always worrying that the enemy might launch an attack, so everyone slept lightly.
Perhaps just one or two gunshots could startle people awake, making it hard to fall back asleep.
Stress, anxiety, even depression.
If it weren't for the alcohol, who knows how one would get through these damn days!
