Yes, if you're enrolled in our high school's Humanities program, you're too young to legally purchase or consume a Gin and Tonic with Lime, but you're old enough to learn about its historic origins.
Starting in the 1750's the English managed India for almost two hundred years. Unaccustomed to living in that part of the world, with its own weather and wildlife, British soldiers were susceptible to contracting malaria. Their physicians encouraged the continuous consumption of small doses of quinine, a medication used even today to prevent malaria.
But quinine tastes very sour, and isn't something that the men wanted to take frequently.
Mixing quinine with carbonated water, the physicians created "tonic water" - you can buy it today in every grocery store. This tasted a little better, and so the soldiers were more likely to drink it.
In order get them all to drink it, however, the tonic water was mixed with gin, the favorite drink of the English soldiers! The British military had also long encouraged the consumption of limes to prevent the scurvy, a disease resulting from lack of vitamin C. So, to complete the beverage, a twist of lime was added.
By the early 1800's, the drink was well-established among the English living in India. As they finished their years of service and returned home, they brought the recipe with them back to Britain. It was no longer needed to prevent malaria, but the taste had become popular.