Yeah, one of the things that makes me write code less is that when I'm really coding well, I'm oblivious to most other things, and after a few hours I surface without much memory to show for what I've been doing. It's like I'm less conscious if I'm really in the zone, and that's scary, so I find excuses to put it off or just do a little here and there. Fortunately, I'm a lot better at breaking things down into "a little here or there" than I used to be. :)

I think you may be confusing what the author is saying with "flow."