Contrary to popular belief do not have caffeine. Those who drink coffee regularly need the caffeine they consume from the coffee just to return them to the same point someone would be who never drinks coffee. It doesn't "wake you up" all it does is return the body to the usual point, all that means is that while you don't have the coffee you are more tired than you usually would be.
It is advised to either never drink coffee or drink coffee every day without missing it. Both ways will leave your body at the usual point. Taking coffee occasionally and then not taking it is the worst thing you can do. (Other than overdosing on caffeine and dying of course which yes can happen.)