This story begins with a very, very simple summary of the film, Singin' in the Rain, for context. But it is primarily focused on Gene Kelly's famous scene, singing and dancing in the rain.
This story and this scene in particular is really effective at getting at the feeling of being in love. You can focus on the film itself, of course, and talk about how Don was smitten by Kathy and didn't even notice the rain. But you can also talk about your own experiences with love. Or loss.
It was also a pretty popular film in its time. Many people remember the first time they saw the movie vividly. You can tell stories about the circumstances seeing the film, who you were with or what it was like.
Finally, film buffs and music and dance afficionados love to talk about the film, the music and the dance. It's a classic and became one of the most beloved musicals of all time.