means My Life is Avatar: The Last Airbender. Your life consists of watching the most awesome fantastic show on the face of the earth and relating it back to your life. If your life is not Avatar: The Last Airbender, you really need to look at your life and look at your choices.
Also, there is a tumblr web log dedicated to this life style. mylifeisavatarthelastairbender.tumblr.com
Today, I got a blue arrow tattoo on my forehead. No one got it's meaning. MLIATLA.