Neutrinos are the most abundant massive particle in the universe, yet we know very little about them due to their elusive nature. Could they be the key to understanding why we live in a matter-dominant universe? Long-baseline neutrino oscillation experiments, such as the ones being conducted at Fermi National Accelerator Laboratory in Illinois, aim to answer many important questions about neutrinos. In this presentation, I discuss what we don’t know about neutrinos, how neutrino oscillation measurements are made and the challenges therein, and a look to the future.