Why....

is it that you can sometimes feel more tired on days when you've done nothing as opposed to those where you've worked hard? Tonight I can hardly hold my eyes open and yet I spent the vast majority of today doing....nothing. Sitting, waiting, fielding a few phone calls. But compared to what I needed to do, I did nothing. Our mainframe system all but crashed and as a result we had no information system all day. We were told just as we were leaving for the day that things were back up and running so we should be able to hit the ground running tomorrow. As a result I should really be wiped out tomorrow night since I have a ton of work awaiting me.