I tell you guys what... I'm still not believing its true... but I just tried it again.
I closed my eye, rested for 30 minutes, and then slowly I could feel it getting harder and harder to concentrate.
When you close your eyes, notice how it just kinda fills up your forehead initially, and all through out the 30 minutes. Then wake up and concentrate on doing a task. Start your stop watch, and feel in your body how that "filled up" feeling just sinks from your eyes as time goes by, and I promise you... it feels like it just slowly sinks down to my gut, and then all of the sudden, my default behaviors kick in, and you find some reason that you just "want" to quit and do something else.
Its like it controls what you conciously "want" to do.
I'll have to try this for 60 minutes next to see if I can feel it sink down for 60 minutes, and then I'll try 90 and 120 ect.... And I wonder how well this follows for longer periods of time... I thought that it could even build up for days, like when I was with my friends for 2 weeks straight... but I might have still confused the effect with other things and it seems like there would be a max point.
There's an idea about chakras how you body is segmented like a worm, and that each chakra takes turns controlling your body, some people are controlled by their stomachs, some by their groins
... maybe this has to do with how our body decides which chakra is going to be in control... I don't know.
Here's another interesting link about how to be creative
Project Renaissance, "Notes Toward the Theory and Practice of Creativity"