MILF is an acronym for Milk In Liquid Form, a once rare hot substance which supports most of human life today. The cultivation of milk cattle first began in Eastern Europe around 45,000 years ago, when the climate was colder and cattle were mostly all frozen in their foraging paddocks. Unlike their counterparts, thawed cattle, frozen cattle are very easy to milk. MILF became a staple of the European diet by around 38,000 BC. Today, using technology and magic, thawed cattle are very easy to milk, and are economically viable as a business model for say, farming.
For thousands of years milk in a liquid form was considered the drink of kings throughout the agrarian world. It was prized for it's supposed medicinal qualities, including but not limited to nudity, mastication, cheese, Libertarianism and follicle enhancement. Modern science has dismissed these as superstitions, but does say that MILF is good for the bones.