well the brain will start working better because what caffeine does is it causes a chemical imbalance in the brain because when we take caffeine into our body it's the exact same reaction as if we're in a crisis and of course our body's not meant to go through crises every day every day and because of that crisis and because of the acid effect that that caffeine has in the body minerals are drawn out of the bones which is our reserves of minerals and after a cup of coffee especially if it's got sugar in it if you would test the urine you would find calcium and magnesium being leached out of the body