Yeah, that's true.. I've found that having a lot of coffee builds up a dependency on the 'kick' and then you start to 'come off' it when the coffee effects are subsiding. Then you feel you need another caffeine hit... it's a roller coaster ride of stimulants. Guys that have a lot of sugar in their coffee have a whole new 'drug' that their body must deal with as they need to get their sugar levels stabilized as well.