I quit caffiene about a decade ago before taking it up again six or seven years later. Quiting wasn't really that great a decision. A lot of the problems that I had attributed to caffiene or caffiene withdrawl such as migraines and periodic brain fog didn't go away without caffiene. Some of the more accute issues did, but I used to get regular insomnia (and still do) and I'd have no crutch to get me through those days after a sleepless night had thown me off balance.

What's worse is that I couldn't really get away from caffiene altogether, things like chocolate contain caffiene as well as a surprising number of drinks which aren't required to advertise their caffine quantity. So I'd occasionally end up getting some caffiene by accident and because I had been avoiding it, I wouldn't have enough of a tolerance to deal with it. I'd have a drink that I didn't know contained caffiene and would suddenly find myself wired with my hands shaking uncontrollably. That hasn't happened since I starting drinking coffee on weekdays again. Having more caffiene than I meant to is still a problem, but not nearly as big a problem as it used to be.