Nobody knows where it comes from...that elusive idea that sometimes materializes in our brains. It's not even in our comfort zone. It's just the nucleus of an idea or even a raw notion of a concept. But it's something and it hooks us. Maybe in the form of a sentence or maybe a theme or maybe some primal event that suddenly gets your mind cooking.
That cooking feeling is what lights the fire under our seats. We can't get it out of our minds. It starts to build momentum. Suddenly a character, your hero, pops into your head. What he or she wants is very clear. What he or she has to do to attain it comes next.
Then the complications and obstacles.
Then the protagonist.
Then you mysteriously know the event that will come at the end of Act One. And the middle of Act Two hiccup arrives. And all of a sudden a subplot comes to mind.
Then you realize what the end of Act Two moment will be. Something unexpected and exciting that will propel you into Act 3.
And maybe you even know how it's going to end.
If you're really lucky you pound out an outline that feels right. Then you start the script. It's not as if the screenplay will write itself, but you're churning out pages faster than ever before and they feel right and you've got your muse riding with you and you're writing in one of those outbursts that rarely come so you know you'd better stick with it because "make hay while the sun shines" keeps reverberating throughout your head.
And you complete the first draft faster than anything you've ever written and you get some feedback from your key readers and they like it and they give you some good notes that feel right and you dive into the rewrite and...
It all started with that raw idea that you weren't even looking for.
Sometimes those are the best inspirations, much better than those other ideas you've been thinking about or making notes for or doing false starts on. Not that they won't materialize into screenplays.
But never underestimate the wild idea that pops into your head.
Like a new friend or a new lover, those are the best kind.