When I was a youngster, the Robert Fulgum books (Everything I needed to know I learned in Kindergarten...etc.) were very popular. (Okay, so I was in HS/college) His third book, It was on Fire When I Lay Down on It was always my favorite if only because it led with the title story: The firemen rescued a guy who was sleeping on a burning mattress. They asked him how the fire started. His reply? "I don't know. It was on fire when I lay down on it." I don't remember a thing about the rest of the book. That was enough to convince my mother would love it, and I bought her the three book boxed set.
This purchase caused a shouting match with my brother who didn't understand why I would buy a bookset written by a Christian minister for my mother. I explained to him about the value of humour and moral teachings, regardless of the source. I don't remember if he understood. That's neither here nor there, really.
This comes up because I was just asked a question about why I defined something a certain way. And of course, the answer is, I didn't, it was on fire when I lay down on it.