Everyone knows (and okay, admit it, secretly loves) the fast-food chain McDonald's -- it's one of the most popular places to eat no matter where you are in the world. But do many people know how the franchise got its start? Here to inform you is the biopic The Founder, which tells the story of a traveling milkshake salesman in 1950s Illinois named Ray Kroc (Michael Keaton) and his somewhat shady history with the chain. While in California he met the McDonald brothers, who churned out burgers and fries at an amazing rate. Kroc teamed with them to turn it into the world's biggest fast-food franchises -- and then essentially pulled it out from under them.

In this clip, find out the secret to McDonald's tasty shakes. Hint: it has nothing to do with real ice cream.