I drank five to six cups a day, and felt like I desperately needed it, and scoffed at anyone who suggested I try getting by with less.

At some point I stumbled on an article about the adenosine receptors in your brain will actually compensate for this much caffeine by just growing more of them. I also read that you can actually "kill" these extra receptors by going cold turkey for a week.

So I did it, and it sucked (the second and third days were the worst). But that was a year ago and I now get an equal if not better effect from two cups a coffee each day.