I think it was an imaginary scenario that Chesterton invented to illustrate a point. There are some preparedness-paradox stories in the book A Libertarian Walk

I think it was an imaginary scenario that Chesterton invented to illustrate a point. There are some preparedness-paradox stories in the book A Libertarian Walks Into a Bear where people who weren't used to living near bears pooh-poohed¹ precautions against them that other people said were necessary. Some of them had never before seen why those precautions might help anything. ¹ Heh.