That's more a fact about the massive volatility of resource-extraction economies than anything else, really. That's how you get things like a projected GDP growth rate of +60% this year and -50% last year in Southern Sudan (those are not typos).
Besides, it's much easier to be "fast growing" when you start from a low base. That's why "fastest growing" almost always indicates hype when used to try to sell you something.
There's a lot of background mess in our mental pictures of the world. We try and be accurate on important issues, but a whole lot of the less important stuff we pick up from the media, the movies, and random impressions. And once these impressions are in our mental pictures, they just don't go away - until we find a fact that causes us to say "huh", and reassess.
Here are three facts that have caused that "huh" in me, recently, and completely rearranged minor parts of my mental map. I'm sharing them here, because that experience is a valuable one.