According to Hersh, "songwriting is about shutting up instead of talking."
Hersh is Kristin Hersh, a songwriter.
This quote reminds me of the old one about writing being easy, just slit your wrists and bleed over the paper, something like that. Possibly less dramatic and drastic sounding, but with the same meaning.
In the end most communication is about shutting off one thing so the flow of ideas can come from another source. Like stop talking and listen instead.
You could go on in this theme of writing and blood and mention about writing being like killing babies. But the babies are your words and ideas. You can’t keep them all. It’s not so much the writing but the editing stage where you have to start killing things in that way.