Your story is like a horse. As a writer, youre on a horse going from Los Angeles to Santa Monica. So long as youre doing scene after scene correctly, you wont have any problems. The problem is that its a buckin brono, a buckin stallion, so youll fall off without realizing it. The horse might go off in the wrong direction. This is all because its difficult to be a screenwriter and youll end up in film lore instead of Santa Barbara. So you have to be careful.
It becomes a joke and advice. Ive heard it from other friends and from one of my professors. I first heard it last year, second semester. Its a metaphor for being true to your story. Each story has its own life. You can mess it up or always keep one scene after the next.
This was an original story told by the professor during class, but has since been passed on by his students to other students and other writers. It symbolizes a hard path to writing the perfect story. A bucking stallion is hard to take control of, and you must be extremely determined to keep it under your control. The way that Matthew told the story does not entirely make sense, and Matt even admitted that he was probably telling the story wrong, but it still signifies the hardship of writing. Writers must stay on course and keep their works cohesive and on topic, instead of wandering on tangents with no purpose.