so used to free writing which is a better fit for novel writing. Screenplay writing is very specific and every scene needs to have a purpose and function to the pace and story as a whole. So by definition it's more of a formulaic writing than free flow writing. It sucks the creativity out of it.
There's the popular-with-youngsters idea that free writing is truly creative, because it's free. If I read a novel and there are chapters that don't serve the overall purpose in some way, I get frustrated. In poetry, each stanza (each word) should be relevant and appropriate. Free writing is useful only in diaries and exercises - not for anything intended to be communicated to others.
But more than that is the complaint I came across often among poets when I was studying writing in college: that form and structure, that limits in general, were antithetical to creativity. In fact, the opposite is true. Limits engender creativity.
Interesting and original art typically comes from the streets, the poor, the oppressed. The people who have the most limits. People whose time, resources, and even daily activities are the most circumscribed.
Interesting and original art creates it's own form, where a form did not exist.
In grad school, I found that wrestling an unformed thought into the bindings of a sonnet, villanelle, or pantoum forced me to exercise my mind in a way that free form poetry does not. Giving it those limits forced me to be more careful with my phrases, and allowed me to play the language against the structure in ways that created meaning that is not possible in free verse. The form allows you to draw attention to specific words by their placement, and to tie one word or stanza to another - through the form - and create layers of meaning. You build layers, like a good wall (or a cake!), and repetition gives it strength. Or like passes of ink over a silkscreen, the color intensifying each time it's pushed through the form.
If you really want to write a screenplay, you want to write something that is identifiable as a movie. Movies have certain specific limits, and the limits of narrative in that medium also create opportunities for creativity. Where else can you have image and reaction? Where you have the complexities of visual storytelling possible in painting paired with the dynamism of movement? Where you can contrast an image or action with sound and create meaning from that? And yet, yes, it has to have a story. It has to have a beginning, middle, and an end. It has to make sense to others. And there's no point in having scenes that, well, don't have a point.
If you really want to write a screenplay, you also have to want to write something that reads well on the page. That does not ramble, that does not turn inward, and that does not waste time on anything that is not the movie. That is tight, and neat, with lots of white space.
If you really want to write a screenplay, you want to write something that moves, on the page. That the reading of it takes you on the journey - whether it's a stroll, a dance, or a hard run. The structure of the segments and scenes, of the short dialogue and brief descriptions are kinetic. Good screenplays use the limits of the medium to create an experience on the page that moves.
Creativity does not end with formula and structure. Creativity rejoices - because like water flowing in a river, it only gets to sing when it passes over the stones.