If you’re like many Americans, you probably start your day with a cup of coffee—a morning latte, a shot of espresso, or maybe a good ol’ drip-brew.
A common explanation among avid coffee drinkers is that we drink coffee to wake ourselves up and alleviate fatigue.
But that story doesn’t completely hold up. After all, the amount of caffeine in a cup of coffee can vary wildly. Even when ordering the same type of coffee from the same coffee shop, caffeine levels can double from one drink to the next. And yet, we coffee drinkers don’t seem to notice….