If you experience some friction with an authority figure today, stand tall. Don't let them intimidate you. They aren't any smarter than you are, they just know things that you don't know: and there is a difference between the two situations. As long as you are polite, you can be insistent in defending what you think. Your input is valuable even when it's not exactly welcome, so don't you dare apologize for voicing your dissent. Even if you're wrong, at least they know that you care.