I had a whole day devoted to dissertating.
I've been trying to push myself to do more than 2 hours of data analysis for the past hour.
I just can't do any more.
I'm not tired; I'm not sleepy; I'm not busy. I just don't want to do any more. Simple.
Sometimes, one just needs to say, "enough is enough," and not force the issue.
I'll be back tomorrow, feeling more motivated.