I was once sitting at a table in a restaurant, eating lunch by myself, when I overheard at a nearby table: "... it's my `N - 1' theory of work: you always work

I was once sitting at a table in a restaurant, eating lunch by myself, when I overheard at a nearby table: "... it's my `N - 1' theory of work: you always work on the second most important thing." It was so true, I burst out laughing.