To show people what they are eating, and how they can help the world by reducing, or stopping the amount they consume. If I only affected me, by virtue of the fact that I no longer eat animals, there will still be some animals left living (or not born at all for food) because I did not eat ever again in my lifetime. Each person who sees me be a Vegetarian and then becomes one or at least eats less meat because of it, saves animals lives!
Vegetarianism is a domino affect. Shortly after I became vegetarian, my mom, followed. I've learned that by example alone can be an inspiration. People see that it can be done and I believe it jars their conscience. So I plan to continue to politely (and sometimes not so much) defend why one should not eat animals and affect more people by eating healthy without meat and showing that we do not need to eat animals. Even one animal saved is worth it!