Yeah, even in instances where one side is clearly right, it's still important to be challenged often enough to know exactly why it's right. As soon as you're comfortable enough with "knowing" something is right without being able to explain why, you risk believing things that "feel" correct but might not be. You don't have to actually argue with trolls, but you should still see and process their arguments enough to formulate a counterargument in your head that would stand up to a hypothetical person arguing in good faith.