Most will stare at bitcoin with eyes wide shut and wait until someone they consider an authority to tell them it's worth anything before they believe it. They still won't understand it, but they will believe it because they were told by someone who "ought to know." And unfortunately, in their mind that authority figure is probably not you. The appeal to power and authority is just how a lot of people choose to live. The best you can do is explain and answer questions when asked, and then be a living example of what you've told them.