The profession itself

Governments, people and corporations around the world have realised the grave importance of adequate education. This may seem a little lofty, but education shapes the future, public policy and public perceptions, and to have a hand in that is humbling. It's a bit hackneyed to think that you're changing the world, but you're certainly doing it some good. English is obviously a lingua franca, and this basic tool opens doors for students. When you teach, you are genuinely changing lives. You will also change when you see how meaningful your profession has become.