I have always had a "thing" for trains. Any kind of trains. Steam engines were my big thing, but if it runs on parallel steel rails I love it. I have watched a Union Pacific "Big Boy" actually hauling freight at speed. Awesome sight. When I was a kid we used to plan family vacations based on maps of the Colorado narrow gauge railroads.
My father and I spent years building a railroad empire in the basement and named it the Saline and Western Hemisphere Railroad. We were not small thinkers. Our cat Freddy would sit watching a tunnel entrance for long periods, so motionless that he became part of the scenery, and when a train came out he would go straight up in the air and flee in panic. He never learned to expect that.
So when I read Paul Krugman today I just had to smile.