Heh, sorry for the late response, finals are coming up and I haven't checked my dA in a while. Yeah, I like to get a latte to wind down and get ready for bed. I'm not entirely sure what causes the reverse, so I can't help you there; but I do know that the stronger it is, the sleepier I become. I'm not certain that its the caffeine, tea and sodas don't effect me too much.
I first learned the effects of coffee when I was dining with friends and we all had IHOPs bottomless coffee, and they were all wound up yet I was on the verge of sleep.
I don't dare take energy drinks, I wouldn't want to even think of the possibilities.