Is there some reason why caffeine (or other stimulants) produce mixed reactions?
Drinking a beverage with caffeine in it perks me up somewhat. I always have a coffee or two in the morning, and usually a cola at lunchtime to keep me from feeling drowsy during the afternoon. But my wife can’t drink any caffeine or she becomes a 33 1/3 played at 78 (remember vinyl, kids?). I mean, the woman simply can’t shut up.
My seven-year-old takes two sips of Mountain Dew and starts bouncing off the walls. Granted, he only weighs what a normal first grader weighs, but even if I chug a whole can of Dew, I’m perfectly capable of sitting still.
How much of this is acclimation and how much of it is the individual’s chemical makeup?