I have a killer headache and yesterday I was sooooooo tired that I slept half the day (work is done for me until after Jan. 1st). I felt so non-productive. Then I realized I hadn't had coffee for a few days. So I'm brewing a cup now, but are these signs of caffeine withdrawal? If so, the headache is a BIOTCH of a headache...lol...and the sleepiness makes ya useless. Notice I've been grumpy too (who me???)!