I don't understand the conclusion that just because he wrote a couple of articles about it ten years apart, that he's been constantly stewing on it for that entire time. Maybe it's something that only occurs to him when he's on the train, and even then maybe only sometimes, and maybe - as a writer - he's trained to recognize these transient thoughts and tease them into articles. That's what a lot of these slice-of-life articles are, focusing on moments that would otherwise slip by and escape notice.