"You're there now doing the thing on paper. You're not killing the goose, you're just producing an egg. So I don't worry about inspiration, or anything like that. It's a matter of just sitting down and working. I have never had the problem of a writing block. I've heard about it. I've felt reluctant to write on some days, for whole weeks, or sometimes even longer. I'd much rather go fishing. for example. or go sharpen pencils, or go swimming, or what not. But, later, coming back and reading what I have produced, I am unable to detect the difference between what came easily and when I had to sit down and say, 'Well, now it's writing time and now I'll write.' There's no difference on paper between the two."
He means that what other people call "writing block" is just a label that bubbles up from within to describe not feeling it. Not feeling like writing. He prefers to label it, "I'd much rather go fishing." And with that belief, he writes anyway. Even expecting it to be rubbish. And then is surprised to look back and see it's comparable to those days on which he didn't have "writing block".
--Frank Herbert (author of Dune)