There are a number of things all stories have in common. All stories begin by establishing a place (real or imaginary) and a time. All stories have characters, and our ability to identify with the characters, and to imagine ourselves into the place and time of the story will help us to be involved in the story. The most compelling thing about stories though, is that all of them work by a process of stating and resolving narrative tension. Let me explain. Very early in a story, a paradox will be stated. That is, there will be two things which are opposites, which cannot be reconciled, but which are somehow tied together. For example, in the story of the Three Little Pigs the story begins by contrasting the safe home of the piglets and the fact that they have to leave it and enter the big wide world. Safe small cosy home/dangerous large scary world: you can have one side of the paradox or the other but not both. The story progresses through time holding these two in tension until the tension is closed with the defeat of the wolf (representing the big wide world) and the tension between the two thus disappears. The story introiduces many other paradoxes - big stupid wolf /small intelligent pig, safe shelter/quick shelter, for example. All get resolved at the closure.
This is important because we are all creatures of paradox. We, all of us, live in the tension between many pairs of these binary opposites. Paul Tillich says there are five common to all people: life/death, potential/actuality, individuality/community, forming a bounded self/extending ourselves to others, creative novelty/traditional patterns. As well as these, there are some common to men or to women, or to children, or to any group you care to name; some are common to our family or tribe and others we hold all on our own. We are caught between poles of literally hundreds, perhaps thousands of paradoxes. And these paradoxes are seldom, if ever resolved. When a story begins, we are interested in the story to the extent that the paradox of the story mirrors one of our own. We listen and receive the gratification of a vicarious ending of one of our tensions as the same tension is closed in the story. This is why, once we begin listening, we cannot leave until we find how the story ends - until we have the tension closed. The skillful storyteller keeps the tension at just the right level: easing it sometimes, increasing it at others, knowing that once the tension is closed, the audience's interest will be reset to zero.
What are the polarities in a story? What things are in opposition? This will give you a clue as to who is telling it and why, and who will be likely to listen to it and why. Thinking of Mama Mia, for example a partial list of polarities might be: beginning/ending; marriage/divorce; old/young; untapped potential/spent energies; together/alone; known/unknown; male/female; youth/age .... and so on. It is the concidence of one of the major polarities of the film with issues we are currently dealing with that will decide, more than cohence of plot or believability of character, whether we are gripped by the film or not, as the case may be.