It’s obvious that something is going on when we ingest coffee. Our insides seem to speed up. Our outsides struggle to catch up. Caffeine mingles with various parts of our nervous system, granting us a focus, mood elevation, and aversion to fatigue. But how does it do this? Is caffeine really so strong as to alter our brain chemicals? And if so, how does it even breach the neurological gates? Surely one of our trusty neurotransmitters would sense deviation and battle the intruder.