"Every day I have 2-3 lines of cocaine, some meth, a fifth of whiskey, smoke a blunt and huff some glue. Am I addicted? I'm not sure..." - LOL

Joking aside, I quit drinking coffee for several years just to know that I could. I work out a lot as well, so I know and use the positive effects of caffeine, but I'm well aware of the negative effects - particularly for me. Everyone is different and you have to learn what affects you and how, and then adjust to keep yourself in balance.