If you’ve seen 300, then you’re very familiar with the Spartan soldiers’ costumes: A helmet, a cape, a shield, and not a whole lot else. Among those Spartans, only one, Gerard Butler’s King Leonidas, has a helmet with a plume on it. Did you know that the real historical Spartans all had plumes on their helmets? Director Zack Snyder decided to change that detail in order to make Leonidas stand out, and easier to identify in the midst of the film’s battle scenes. That’s just one of the facts featured in the newest episode of You Think You Know Movies!