I will get headaches if I don't get my caffeine at the right time. Bad ones. And what sucks is that even when I do get the caffeine it doesn't help the headache. I will also get nauseous. I've tried to stop coffee many times but I've never been able to say off....I went up to a year and never felt like myself. People underestimate just how addictive it is.
I've been drinking coffee since I was about 4 so that's a little ridiculous though...
Funny thing is that if I drank one of those drinks I probably wouldn't feel a damn thing as far as energy wise. I need caffeine just to feel normal.