We don't need science to tell us that coffee is addictive. Although plenty of research shows that it's perfectly healthy to drink, you can easily become dependent on it if you indulge every day.
That doesn't mean giving it up every day is easy, however — withdrawal leads to fatigue, irritability and horrible headaches.
So why is it so challenging?
According to Food & Wine, caffeine sticks to the brain's receptors, taking the place of a neurotransmitter called adenosine. Adenosine generally keeps you calm and cool, whereas caffeine does the opposite.
Your confused brain then tries to overcompensate and generates extra adenosine. So when you quit cold turkey, you're likely to get a killer headache.
The good news is, however, if you aren't drinking more than the recommended limit of four 8-ounce cups or experiencing any side effects, there's no need to put yourself through that.