There's this weird, frustrating, space. Where you have a teeny bit of a story just visible in the far, foggy distance. Maybe you have the sketch of a character, or you hear a line or two of dialogue, or you know the last line. You want to start writing, but experience has taught you that you just don't know enough yet. So you wait. You take a bath, or take a walk, or do the dishes. And slowly, slowly, more bits emerge, until finally, you have enough -- enough to start with, at least. You finally start to write your story. And the frustrating slips away, replaced by satisfaction. Sometimes by bliss.
All of this process is severely slowed down by Facebook, I have to say. :-)