In 1883, Sigmund Freud was a young neurologist living in Vienna and struggling to make ends meet. Like many doctors, he became interested in a South American drug that was all the rage, cocaine. On April 30, 1883, he took a dose of pure cocaine for the first time. He evaluated its effects on mood, strength and reaction times and wrote up his findings in a pamphlet called Über Coca, or “On Cocaine”. His comments read: “Long, intensive physical work is performed without any fatigue… This result is enjoyed without any of the unpleasant after-effects that follow exhilaration brought about by alcohol… Absolutely no craving for the further use of cocaine appears after the first, or even after repeated taking of the drug.” Like other doctors of his time, Freud failed to recognize that cocaine is highly addictive – he actually recommended it as a treatment for morphine addiction. But, he did make one fascinating observation. Applied to the tongue or nose, cocaine produces a profound local numbing. Freud mentioned this to his colleague Karl Koller, an eye specialist who immediately saw its potential and later used it to transform eye surgery. In non-addictive forms, cocaine’s offspring are now widely used as local anaesthetics in medicine. If Freud had followed through with his original insight, that cocaine is an anaesthetic, he would probably have stayed a neurologist and never found the time to invent psychoanalysis.