I'd agree that its just natural. Embrace it and when you're feeling productive, see how long you can go.
I think society/ourselves have put arbitrary time barriers in our days where things occur - meals, bedtimes, work days, etc. Sometimes it would be nice if you find yourself in a "flow" state to just ignore all of those barriers and roll with it for a while. Its like some days you just aren't that hungry or you sleep much longer/shorter. We are animals after all and sometimes believe we can control things to the point of robotic measurable output when our bodies tell us otherwise.
I think society/ourselves have put arbitrary time barriers in our days where things occur - meals, bedtimes, work days, etc. Sometimes it would be nice if you find yourself in a "flow" state to just ignore all of those barriers and roll with it for a while. Its like some days you just aren't that hungry or you sleep much longer/shorter. We are animals after all and sometimes believe we can control things to the point of robotic measurable output when our bodies tell us otherwise.