[A sidelong glance. His world lacked magic, and 'bending' could arguably come under that umbrella - so not knowing the Avatar is not as surprising as it could have been.]

On my world, there are four primary elements. Fire, Water, Air and Earth. All beings have the latent potential to control one of them. Both myself and Bolin, for example, are earthbenders.

Only one person in the entire world is born with the ability to control all four elements; they are known as the Avatar, and it is their duty to ensure balance in the world.