Yeah caffeine doesn't stay in the body all that long. If you stop all intake it will basically all be metabolized or eliminated within 24 hours. For most people, the effects diminish earlier than that, usually from 6-12 hours. It's not something that requires a long detox period. If you want to quit and are getting headaches, take an aspirin/tylenol/advil (check that they don't contain caffeine!) and drink plenty of water. I've found the headaches pass after a day or two.