Since coffee is pretty much universally accepted in the world (even more so than alcohol), one can easily view a strong coffee habit as normal, or at worst a benign vice. And it's fine as far as addictions go; you can ride the caffeine wave to increased productivity, and when the effects wear off another cup of liquid inspiration is there waiting. I did this for close to 15 years.
What bothered me was this feeling of being ruled by the habit. I simply had to have my two jam packed triple espresso lattes (or equivalent when not at home), one in the morning, and one in the afternoon; there was never serious consideration given to the thought, "I know, let's not have coffee this weekend", just a steamroller habit with me along for the ride.
Ironically what got me to quit coffee (and I had no intention of doing so) was a "retreat" in Mexico where one of the requirements was following a strict diet 2 days before and 4 days after the experience. One of the restrictions was no coffee, which part of me was strongly resisting, to the point of considering withdrawing (hah) from something I'd already spent several hundred dollars for.
In the end I went ahead with it. On the 4th day after the retreat I was free, and commenced preparing a strong pot of rocket fuel, but then something within me realized, "wait, I don't need this anymore".
And I don't, at all. Coffee is the devil made liquid -- proceed with caution :)
[0] i.e. even when sick, on off days from work, during vacation, etc.