After fighting in WWI, A. A. Milne…
After fighting in WWI, A. A. Milne had PTSD so severe, he was reminded of whizzing bullets by buzzing bees, and cannons firing by balloons popping. Wanting a lighthearted distraction and a way to explain to his son the difficulties of war, he wrote Winnie the Pooh stories as his way of doing so. Source