One thing I've realized since then is that writing is a sport too; it takes conditioning. You have to write every day to build your sentence-level craft. You have to write your way out of hundreds of plot-tangles and character breakdowns to develop sufficient problem-solving reflexes. And until you've written a novel in one focused stretch, you can't build up the muscles it takes to keep 80,000 words of plot and character arcs in your head, which is a hard, hard thing to do.
I would probably change that "every day" to something wishywashier like "a whole lot" or "heaps, and maybe every day for a few good stretches of time", but apart from that I'm with him