...eventually you tend to go back and read yourself. And perhaps you realize how small and claustrophobic your skull has become. And perhaps you want out.
So you don't write for a while.
Then words come and come, racing and leapfrogging to the front of things until they insist to be set in type. It no longer matters if writing is worthwhile, if you have an audience, if you're improving a craft or spilling your ugly guts. Writing is better, you hope, than trapping the words in the ever-shrinking real estate of your brain. Anything, when trapped, displays its most primal side. Something trapped will hide in a shell or lash out, hopelessly but nevertheless driven by animal instinct to flail against its cage.
Don't mind my flailing words. Once I start letting them out in the light here and there they will settle down. Their wings will flutter then fold, and they will know they have all the time in the world to pass on their tiny messages.