We've all been in that state of high performance where suddenly its 2am and you think "ok 5 more minutes" then its suddenly 4am.
I would liken a lot of what he is saying there to a kind of trance state, similar to self hypnosis, where there is only the work in front of you.
I get into this state most often when I sit down to produce any kind of art, I spit and spat around starting but then after a while settle into it and can spend hours working on something, its a whole different feeling to just regular doodling, its all encompassing.