" No worries" is the best thing to happen to sullen teenagers since I was one - even better than vampire sexting, GTL, or Call of Duty. When I was a sullen teenager, we had to make do wtih the vastly inferior "whatever". "No worries" beats "whatever" six ways to Sunday. I'ts a vaguely mystical way of saying "I hear your mouth make noise, saying something that I plan to ignore." It has a noble Rasta-man vibe, as if you're quoting some sort of timeless yet meaningless proverb on the nature of change - "Soon come," or "As the cloud is slow, the wind is quick." In terms of ignoring provocation, "no worries" is just about perfect. "