It was surprising to see that stories do not need to initially fit into a clear theme as long as you are able to tie it all together in a coherent way at the end. Your intention does not need to be in your face obvious—it can slowly become apparent as the story progresses. In fact, it's more effective this way than if you just bludgeon the reader over the head with your message. I learned that essays that incorporate many stories and essays that incorporate only one can be equally effective, although I think at this stage I'm partial to essays that don't include more than, say, four or so stories.