We all have misconceptions about the world in which we live--how it works, how we interact with it, how it changes, and the reasons behind those changes. These misunderstandings are personal notions we create to make meaning of our surroundings. Often, these misunderstandings go unchallenged for a lifetime. This article addresses how these inaccuracies can occur, what historic missteps may contribute, and which strategies teachers can use to help students move toward conceptual change. (Contains 3 figures and 2 online resources.)