When you work with a good actor, there is this natural rapport and chemistry that develops over time. That chemistry helps your characters come alive and makes the story of the film that much more convincing.
A love affair is like a short story--it has a beginning, a middle, and an end. The beginning was easy, the middle might drag, invaded by commonplace, but the end, instead of being decisive and well knit with that element of revelatory surprise as a well-written story should be, it usually dissipated in a succession of messy and humiliating anticlimaxes.
From earliest times, humans - explorers and thinkers - have wanted to figure out the shape of their world. Forever, the way we've done that is through storytelling. It is difficult to let the truth get in the way of a good story.