At first I only hear the birds and when they are not there I think it is quiet. But after a while—a long while, I think—I notice that I am having an idea instead of hearing. And when I notice the idea, I instantly stop having it. Like when you are not very deeply asleep and you become less deeply asleep because of a click in your brain and then you are suddenly aware you were more deeply asleep than you knew but also aware that even now you are not yet exactly awake.