I finally did it.
It used to be that every year I would take a week off coffee, consume no caffeine for a full week - just to show that I could. About 4 years ago I tried this for the first time in a few years, and failed. On day two, I felt really sick. To the point that I had to go home from work. Later that day I had a coffee. Perhaps it was just coincidence, perhaps I was getting sick anyway - but it took four years for me to try it again.
This time I decided to do things gradually, rather than cold turkey. Over a span of the past 3 months, I gradually reduced my coffee intake from 4 cups a day to 3 cups a day and then to two cups a day. After that, I reduced it to one cup in the moring and a cup of Yerba Mate tea in the afternoon (Yerba Mate is an organic tea that contains some naturally occuring caffeine - not a lot - and 149 nutrients). Finally, 3 weeks ago, I eliminated the coffee altogther, having Yerba Mate in the morning and afternoon. A week later, it was only one cup of Yerba Mate, in the afternoon. Then finally last week zero caffeine for the entire seven days. I had some minor headaches, but nothing too bad, since I stepped things down slowly.
I am now drinking my first coffee in three weeks. Going forward, I am still going to drink coffee, of course, but probably not as much. :)