My grandmother used to tell me stories about the old days, a time of peace when the Avatar kept balance between the Water Tribes, Earth Kingdom, Fire Nation, and Air Nomads. But that all changed when the Fire Nation attacked. 

Ugh, I'm embarrassed to be related to you! Ever since Mom died I've been doing all the work around camp while you've been off playing soldier!

Maybe. But we haven't had contact with our sister tribe in a long time. It's not exactly 'turn right at the second glacier.' It's on the other side of the world.