Most of us know and love caffeine, the central nervous system stimulant that naturally occurs in coffee beans and gives our pour-overs and cold brews their energy-boosting magic. Something even the most seasoned coffee lover may not be aware of, though, is the fact that decaffeinated coffee, is not, in fact, 100 percent caffeine-free. That’s right, folks: There is caffeine in your decaf. GASP. Here’s what you need to know about why that is, how much caffeine we’re talking about, and whether it even matters.