I tried cutting down on my coffee intake for a week. End result: I felt like I was getting stupider. There was a weird hollow feeling in my brain that I didn't like at all, and I was starting to worry I had damaged myself somehow. However, after three good, big cups of coffee, I feel normal again and things are buzzing along. I guess my normal state is dehydrated, exhausted, and wired. 
Comments
Darren
I tried doing that about 6 months ago. After the first day of no coffee, I developed a splitting headache. Morning of the second day the headache had kind of left, but was lingering a little bit, although I had a really strange sensation like I wasn't balanced and I was a little jittery. I decided to just continue with my coffee drinking. It has some anti-oxidants in it and the caffeine boost helps my workouts.