At the simplest level, a story is about a hero overcoming physical obstacles to achieve a goal. While this can be visually interesting, it can get dull after a while. Just watching physical action means little if you don’t also have an emotional stake in the hero.
The best conflict doesn’t just involve physical struggle but also emotional struggle as well. Now the hero must choose between two conflicting emotions and their actions move them closer to making that final decision.
The heart of this conflicting emotion comes solely from the hero’s change. In the beginning, the hero is one way but by the end, the hero is another, hopefully better person. This conflict between the hero’s own selves is what drives emotional conflict from start to finish.
In “Titanic,” Rose is initially passive, letting life happen to her and dreading a life in a marriage to a rich man she doesn’t like. By the end, Rose becomes an active character who embraces and chooses her own life. That conflict is what tears her apart at all times and we can see that conflict appear in her physical obstacles.
One of the first obstacles occurs when she thinks about throwing herself off the ship to kill herself. She no longer wants to allow life to happen to her, but she thinks her only option is to commit suicide. That’s her active self trying to pull her out of her passive life.
Once Rose manages to overcome this obstacle with the help of Jack, her next obstacle is inviting Jack to dinner with all the rich people. Now she’s torn between going back to a passive life or actively enjoying Jack’s company over her fiancé’s company. That’s why Rose later goes with Jack to dance with him with the third class passengers.
Another physical obstacle is when Rose is safely on a lifeboat but Jack is trapped. rose could passively let herself be let down in the lifeboat but she makes the active decision to jump out and get back on the Titanic to save Jack.
Notice that each time, Rose is faced with a choice to remain passive or become active. Each physical obstacle forces her to choose and then overcoming that physical obstacle slows pushes her towards becoming the active person she becomes in the end.
Without this emotional inner conflict, all Rose’s physical obstacles would mean little, but with this emotional inner conflict, all her physical obstacles are ways of showing her growing and becoming stronger. That’s what makes a story far more interesting when you have inner emotional conflict hidden inside physical conflict.