Epicurean philosophy teaches you to immunize yourself against many impositions by giving you a basic orientation toward the universe that helps defeat those negative forces in life.
There are so many things that are part of common culture that have nothing to do with a living a pleasant, pleasurable, and "blessed-as-if-living-like-the-gods" life -- and they are all just "empty opinion" (I'm especially talking about what we buy, and what we think we should buy, based on what everyone else is doing - food, clothing, home decor, etc.