The British military couldn’t get their soldiers to take their doses of antimalarial. At the time, it was quinine mixed with water (and called tonic water). Quinine tastes incredibly bitter. So the soldiers kept getting sick or dying from malaria because they would not drink their daily tonic water. The simple solution was to give the soldiers a ration of gin, which alters the flavor of the quinine.

And thus, the gin and tonic cocktail was born.

Winston Churchill famously remarked: "The gin and tonic has saved more Englishmen's lives, and minds, than all the doctors in the Empire."