I wrote a blog post a while ago describing my love of coffee. It's undiminished. But from 4 or 5 cups then, I have cut down to 1 cup only, first thing in the morning. And even stranger, I have now made that cup decaffeinated.
First day today and I can report that the coffee's not bad, but not as good as my usual (a bit more bitter). Even 1/2 hour after, I could tell it was decaff. But the major difference was from mid-morning until the mid-afternoon. A background low-level headache and feeling much more tired than usual. A big difference to my day in fact, even though I'm still drinking a few cups of tea a day.
I'm not keen on feeling physically dependant on anything, so I think I'll carry on with this "experiment", flush it out a bit and see what happens. My physical reaction just shows how strong coffee can be.
At some point however, I definitely want to try Kopi Luwak coffee. This is the coffee made from the beans eaten and excreted by a civet! Gourmet coffee apparently.