The link between coffee and high energy is obvious; as caffeine seeps into the wirings of our mind and body, increasing heart rate and stimulating the nervous system, those quintessential, caffeinated bursts of energy are undeniable – and rather exciting! You go from trudging and whining to dancing and laughing. From hazy to laser-focused. From a zombie to a mad scientist. And while there is a much more complicated process going on in your brain, the simple explanation seems to be: coffee makes us happy.