I'm in the same pattern. After I have given up coffee for a few months, one coffee is enough to get me addicted again. It's so much more potent.
It's worth quitting just to go back to it. I seriously love falling off the wagon.
When your bad, your better!
I go back to coffee for two reasons:
1. Invariably I hit a stretch of life that requires great effort and I just /need/ a cup of coffee (last year it was a week with 2 transatlantic flights followed by a conference presentation).
2. Iced Coffee in the Summer makes life worth living. It is a true joy of life, and I always tell myself "just this one time."