I too like to weave in layers of meaning, Damei. But I am trying to do what Mr King told me ! (been reading Stephen King's 'On Writing') ...which is, look for themes after you've written a cracking story, rather than make your story march to the beat of your wonderfully profound messages. Not easy, but I think that the whole 'put your characters - personalities and all - into a situation and see how they react, think, move, and generate consequences' is one of the keys to producing engaging writing.